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1295 Cards in this Set
- Front
- Back
what are the four major causes of weight gain?
|
growth
increase in lean body mass increase in fat increase in fluid |
|
which two elements comprise normal body composition?
|
lean body mass and adipose tissue
|
|
what is the commonest cause of weight gain?
|
increase in adiposity
|
|
name some endocrine conditions that cause weight gain
|
hyperinsulinaemia
type 2 diabetes acromegaly cushing's hypothyroidism raised prolactin levels |
|
t/f... extremely high alcohol intake is associated with excess adiposity
|
false
|
|
what secretes insulin?
|
beta cells of the pancreas
|
|
what is the main signal for insulin secretion?
|
rise in blood glucose levels above 5 mM
|
|
what is the effect on cAMP when cells bind insulin?
|
intracellular levels of cAMP are lowered
|
|
t/f... the brain needs insulin for glucose transport
|
false
|
|
t/f... insulin inhibits the movement of GLUT-4 glucose transporters from the cell membrane to the Golgi apparatus
|
true
|
|
t/f... glucose transport into the liver is not possible unless insulin is present
|
false
|
|
t/f...insulin inhibits lipolysis
|
true
|
|
how does insulin keep cAMP levels low?
|
by stimulating phosphodiesterase which breaks down cAMP
|
|
what effect does insulin have on leptin levels?
|
insulin increases leptin levels
|
|
t/f... leptin acts as a satiety factor in humans
|
false
|
|
t/f... dietary fibre may lower cholesterol
|
true
|
|
what is the most effective fatty acid in lowering LDL cholesterol?
|
linoleic acid
|
|
which racial groups are at higher risk of familial hypercholesterolaemia?
|
Lebanese, South African and French Canadians
|
|
what has impaired function in familial hypercholesterolaemia?
|
LDL receptors
|
|
describe the dyslipidaemia in metabolic syndrome
|
raised triglycerides
low HDL LDL normal or marginally elevated |
|
what is the mechanism of action of sulphonylureas?
|
potentiate glucose stimulated insulin release
|
|
what is the most important side effect of sulphonylureas?
|
hypoglycaemia
|
|
what is the most important side effect of metformin?
|
lactic acidosis
|
|
what is the drug of first choice in obese Type 2 diabetes patients?
|
metformin
|
|
where does the alimentary tract start and end?
|
oral cavity
anus |
|
where does the gastrointestinal tract begin?
|
stomach
|
|
what comprises the small intestine?
|
duodenum
jejunum ileum |
|
name the four parts of the colon
|
ascending colon
transverse colon descending colon sigmoid colon |
|
which vertebral level does the oesophagus start at?
|
C6
|
|
t/f... the part of the oesophagus in the abdominal cavity is very long
|
false, it is very short
|
|
what is the only part of GI tract not in the abdominopelvic cavity?
|
anal canal (in the perineum)
|
|
what parts of the alimentary tract are derived from the foregut?
|
oesophagus, stomach, proximal duodenum
|
|
at which point does the foregut end?
|
proximal duodenum (at entry of bile duct)
|
|
which parts of the alimentary tract are derived from the midgut?
|
distal duodenum
jejunum ileum ascending colon 2/3 transverse colon |
|
what is the end of the true gut?
|
pectinate line (halfway along anal canal)
|
|
which organs are associated with the foregut?
|
liver
most of pancreas spleen |
|
which organs are associated with the midgut?
|
lower part of head of pancreas
|
|
what is the arterial supply to structures derived from the foregut?
|
coeliac trunk
|
|
what is the arterial supply to structures derived from the midgut?
|
superior mesenteric artery
|
|
what is the arterial supply to structures derived from the hindgut?
|
inferior mesenteric artery
|
|
which vein drains the structures derived from the foregut?
|
splenic vein
|
|
which vein drains structures derived from midgut?
|
superior mesenteric vein
|
|
which vein drains structures derived from hindgut?
|
inferior mesenteric vein
|
|
what is the lymphatic drainage of the foregut structures?
|
coeliac nodes
|
|
what are the ganglia associated with the base of the coeliac trunk?
|
coeliac ganglia
|
|
t/f... the arteries supplying the GIT are unpaired
|
true, they come off the front of the aorta in the midline
|
|
the coeliac trunk is at which vertebral level?
|
T12
|
|
which artery comes off the aorta at vertebral level L1?
|
superior mesenteric artery
|
|
the inferior mesenteric artery is at which vertebral level?
|
L3
|
|
which artery comes off the aorta just above the superior border of the pancreas?
|
coeliac trunk
|
|
which artery comes off the aorta behind the neck of the pancreas?
|
superior mesenteric artery
|
|
which direction does the inferior mesenteric artery go after branching from the aorta?
|
to the left
|
|
which branch of the coeliac trunk goes to the right?
|
common hepatic artery
|
|
which two branches of the coeliac trunk go to the left?
|
left gastric artery
splenic artery |
|
what is the arterial supply to the ascending colon?
|
right colic artery
|
|
which two branches of the superior mesenteric artery travel superiorly?
|
inferior pancreaticoduodenal artery
middle colic artery |
|
which artery supplies the descending colon?
|
left colic branch of inferior mesenteric artery
|
|
what is the name of the inferior mesenteric artery in the pelvic cavity?
|
superior rectal artery
|
|
what is the marginal artery?
|
anastomoses between colic arteries
|
|
which two veins form the portal vein?
|
splenic vein
superior mesenteric vein |
|
where do the splenic and superior mesenteric veins join to form the portal vein?
|
behind neck of pancreas
|
|
which vein does the inferior mesenteric vein usually join?
|
splenic vein
|
|
what does the portal vein travel in?
|
lesser omentum (free edge)
|
|
what are the sites of portacaval anastomoses?
|
wall of lower oesophagus
wall of rectum and anal canal umbilicus retroperitoneal |
|
which side of the aorta is the cisterna chyli on?
|
right
|
|
which vertebral level is the cisternal chyli at?
|
L1-2
|
|
what is the role of parasympathetic innervation of the GIT?
|
increased peristalsis and secretions
|
|
what is the effect of sympathetic innervation of GIT?
|
decreased peristalsis and secretions
vasoconstriction |
|
what is the parasympathetic supply to foregut and midgut?
|
vagus nerve
|
|
what is the parasympathetic supply to hindgut?
|
pelvic splanchnic nerves (S2-4)
|
|
what are the sympathetic splanchnic nerves to the GIT?
|
thoracic
lumbar |
|
where does the foregut refer pain to?
|
epigastrium
|
|
where does the midgut refer pain to?
|
umbilical region
|
|
where does the hindgut refer pain to?
|
hypogastrium
|
|
which structures of the GIT may refer pain to the back?
|
secondarily retroperitoneal structures
|
|
which part of the gut has a ventral mesentery?
|
foregut
|
|
t/f... all parts of gut have a dorsal mesentery
|
true
|
|
t/f... all parts of gut have a ventral mesentery
|
false, only the foregut has a ventral mesentery
|
|
what does the lower free edge of the ventral mesentery become?
|
free edge of falciform ligament and lesser omentum
|
|
where do the liver and spleen develop?
|
liver - ventral mesentery
spleen - dorsal mesentery |
|
which structures are suspended by mesentery?
|
jejunum
ileum |
|
which structures are suspended by mesocolon?
|
transverse colon
sigmoid colon |
|
which structures are secondarily retroperitoneal?
|
duodenum (except first few cm)
ascending colon descending colon |
|
where is the epiploic foramen?
|
behind free edge of lesser omentum
|
|
which section of the gut tube elongates quite rapidly?
|
midgut loop
|
|
where does the midgut loop herniate into?
|
umbilical cord
|
|
when does the physiological herniation of the midgut loop into the umbilical cord occur?
|
between 6th and 10th week
|
|
how does the gut tube rotate?
|
270 degrees counterclockwise
|
|
what stabilises the rotation of the gut tube?
|
fusion of mesenteries
|
|
how much fluid is contained in the peritoneal cavity?
|
5-10ml
|
|
where do the greater and lesser sac communicate?
|
epiploic foramen
|
|
t/f... intraperitoneal structures lie within the peritoneal cavity
|
false, they are almost completely invested by peritoneum
|
|
what is ascites?
|
pathological accumulation of fluid in peritoneal cavity
|
|
in what situation is the peritoneal cavity completely closed?
|
male
|
|
why do ascending infections of peritoneum occur in females?
|
female peritoneal cavity communicates with the exterior via the genital tract
|
|
what is the rectovesical fossa?
|
fossa between rectum and bladder in peritoneal cavity
|
|
which layer of peritoneum has somatic dermatomal sensory innervation?
|
parietal peritoneum
|
|
what divides the supracolic and infracolic compartments?
|
transverse colon
|
|
t/f... the pancreas is an intraperitoneal organ
|
false, it is a retroperitoneal structure
|
|
which organs are in the supracolic compartment?
|
liver
gall bladder spleen stomach pancreas part of duodenum |
|
what attaches the liver to the anterior abdominal wall?
|
falciform ligament
|
|
the median umbilical ligament is the remnant of...
|
the urachus (attaches bladder to umbilicus)
|
|
the medial umbilical ligaments are...
|
obliterated umbilical arteries
|
|
what are the sites for internal herniae in the peritoneal cavity?
|
foramen of Winslow
duodenojejunal flexure region iliocaecal region sigmoid mesentery region |
|
what is zygosis?
|
fusion of two or more layers of peritoneum to form a single layer
|
|
which structures become secondarily retroperitoneal?
|
right and left colons, pancreas, duodenum
|
|
what are the lateral umbilical ligaments?
|
inferior epigastric vessels
|
|
which areas does the oesophagus traverse?
|
neck, thorax, abdomen
|
|
which muscle prevents food or air from entering the oesophagus except when swallowing?
|
cricopharyngeus (lower part of inferior constrictor muscle)
|
|
what is the upper oesophageal sphincter?
|
cricopharyngeus
|
|
where does the pharynx become the oesophagus?
|
lower border of cricoid cartilage (CV6)
|
|
where does the epithelium of the oesophagus change from stratified squamous to columnar?
|
at the squamo-columnar junction (Z-line)
|
|
t/f... oesophageal mucosa is tightly connected to muscle
|
false, it is loosely connected to muscle
|
|
what type of muscle is present in the oesophagus?
|
upper 1/3 - skeletal muscle
middle 1/3 - mixed middle 1/3 - smooth muscle |
|
what is the function of the lower oesophageal sphincter?
|
prevents reflux
|
|
how long is the oesophagus?
|
25cm
|
|
what is located posterior to the oesophagus in its upper and lower parts?
|
upper - C7 and thoracic vertebra
lower - thoracic aorta |
|
what is anterior to oesophagus?
|
trachea, lymph nodes, pericardium and heart
|
|
what are the constriction points of the oesophagus?
|
upper oesophageal sphincter
arch or aorta and left principal bronchus oesophageal hiatus |
|
what forms the oesophageal hiatus?
|
encircling fibres of right crus of diaphragm
|
|
t/f... the oesophagus passes through a tendinous part of the diaphragm
|
false, it passes through a muscular part of the diaphragm
|
|
what is the blood supply to the oesophagus in the
a) cervical part b) thoracic part and c)abdominal part? |
a) branches of inferior thyroid artery
b) branches of descending thoracic aorta c) left gastric artery (branch of coeliac trunk) |
|
what is the venous drainage of the abdominal oesophagus?
|
portal vein
|
|
what is the venous drainage of the thoracic oesophagus?
|
azygos vein -> SVC
|
|
what is the venous drainage to the cervical oesophagus?
|
thyroid veins -> SVC
|
|
which part of the oesophagus drains to the deep cervical nodes?
|
cervical part
|
|
which part of the oesophagus drains to the mediastinal nodes?
|
thoracic part
|
|
which part of the oesophagus drains to the coeliac nodes?
|
abdominal part
|
|
which nerve forms an oesophageal plexus?
|
vagus
|
|
what is the innervation of the oesophagus?
|
vagus and sympathetic trunk
|
|
where does oesophageal pain refer?
|
retrosternally
|
|
t/f... trachea develops as anterior diverticulum from primitive foregut
|
true
|
|
what divides the fundus from the body of the stomach?
|
a horizontal line drawn through the cardiac notch
|
|
what is the part of the stomach distal to the angular notch?
|
pyloric part (pyloric antrum and pyloric canal)
|
|
what are the folds on the internal surface of the stomach called?
|
rugae
|
|
how many muscular layers does the stomach have?
|
3 - longitudinal, circular and oblique layers (from superficial to deep)
|
|
which layer forms the pyloric sphincter?
|
circular layer of muscle
|
|
which omentum attaches from the lesser curvature?
|
lesser omentum
|
|
what is the portal triad?
|
portal vein
bile duct proper hepatic artery |
|
what are the two parts of the lesser omentum?
|
hepatogastric ligament
hepoatoduodenal ligament |
|
which three ligaments comprise the greater omentum?
|
gastrophrenic ligament
gastrosplenic ligament gastrocolic ligament |
|
what lies anterior to the stomach?
|
liver
diaphragm anterior abdominal wall |
|
what lies posterior to the stomach?
|
lesser sac
|
|
what is the superior boundary of the epiploic foramen?
|
liver
|
|
what is the inferior boundary of the epiploic foramen?
|
duodenum
|
|
what lies anterior to the epiploic foramen?
|
lesser omentum with portal triad
|
|
what lies posterior to the epiploic foramen?
|
IVC
|
|
what is the commonest type of hiatal hernia?
|
sliding hiatal hernia
|
|
how long is the duodenum?
|
25cm
|
|
which part of the duodenum is mobile?
|
the first few cm (attached to omenta)
|
|
how many parts does the duodenum have?
|
4
|
|
what are the parts of the duodenum and at what vertebral level are they situated?
|
superior - L1
descending - L2 horizontal - L3 ascending - L2 |
|
what side does the duodenum end on?
|
left
|
|
what side is the duodenum located on?
|
mainly to right of midline
|
|
which ducts open at the major duodenal papilla?
|
bile duct
main pancreatic duct |
|
which duct opens at the minor duodenal papilla?
|
accessory pancreatic duct
|
|
what is the blood supply to the fundus of the stomach?
|
short gastric arteries
|
|
what supplies the lesser curvature of the stomach?
|
R and L gastric arteries
|
|
what supplies the greater curvature of the stomach?
|
R and L gastroepiploic arteries
|
|
which artery may be eroded by a peptic ulcer on posterior wall of stomach?
|
splenic artery
|
|
which artery may be eroded by a peptic ulcer on posterior wall of first part of duodenum?
|
gastroduodenal artery
|
|
what does the gastroduodenal artery branch into?
|
superior pancreaticoduodenal artery
R gastroepiploic artery |
|
what is the venous drainage of the stomach and duodenum?
|
portal vein
|
|
what is the blood supply to the spleen?
|
coeliac trunk
|
|
what is the venous drainage of the spleen?
|
portal vein
|
|
what is the largest organ in the body?
|
liver
|
|
what covers the liver anteriorly in the midline?
|
rectus abdominis
|
|
how far down does the lung extend in the mid axillary line?
|
rib 8
|
|
how far down does the pleura extend in the right midaxillary line?
|
rib 10
|
|
how far down does the liver extend in the right midaxillary line?
|
rib 11
|
|
what are the two surfaces of the liver?
|
diaphragmatic
visceral |
|
what separates the right and left lobes of the liver?
|
falciform ligament (and ligamentum teres)
|
|
what does the ligamentum teres attach the liver to?
|
umbilicus
|
|
what delineates the left and right anatomical lobes of the liver posteriorly?
|
fissure for ligamentum teres and fissure for ligementum venosum
|
|
what is ligamentum teres the remnant of?
|
umbilical vein
|
|
what divides the liver into its functional lobes?
|
IVC and gall bladder
|
|
where is the caudate lobe of the liver?
|
between fissure for ligamentum venosum and IVC
|
|
where is the quadrate lobe of the liver?
|
between fissure for ligamentum teres and gall bladder
|
|
what forms the falciform ligament?
|
two layers of peritoneum
|
|
what is the bare area of the liver?
|
the area of the liver between the superior and inferior layers of coronary ligament not covered by peritoneum
|
|
where does lymph from the bare area of the liver drain?
|
through diaphragm to thoracic nodes
|
|
what is the lymphatic drainage of the liver?
|
via porta hepatis to coeliac nodes then to cisterna chyli
|
|
what ligament is formed by the union of the superior and inferior layers of coronary ligament?
|
right triangular ligament
|
|
what is the most commonly infected area in the abdominal cavity?
|
hepatorenal recess (pouch of Morrison)
|
|
which structure of the portal triad is most posterior?
|
portal vein
|
|
which structure lies anteriorly on the left in the free edge of the lesser omentum?
|
proper hepatic artery
|
|
where is the bile duct located in the free edge of the lesser omentum?
|
anterior and to the right
|
|
what is another name for the portal triad?
|
hepatic pedicle
|
|
where does the blood from the portal vein and hepatic artery mix?
|
sinusoids of the liver
|
|
what is the venous drainage of the liver?
|
hepatic vein -> IVC
|
|
name some viscera that drain by the portal vein
|
stomach
intestines pancreas spleen |
|
what forms the common hepatic duct?
|
R and L hepatic ducts
|
|
what joins the bile duct at the ampulla of Vater?
|
main pancreatic duct
|
|
where does the bile duct open into the duodenum?
|
major duodenal papilla
|
|
what is the storage capacity of the gall bladder?
|
40-50ml
|
|
what allows the release of bile by the gall bladder?
|
contraction of smooth muscle in the wall of the gall bladder and relaxation of sphincters (when food is in the duodenum and cholecystekinin is released)
|
|
when does the hepatic duct become the bile duct?
|
when the cystic duct joins the hepatic duct
|
|
t/f... the bile duct passes anterior to the duodenum
|
false, it passes behind the duodenum
|
|
what gives bile its colour?
|
bile pigments (breakdown products of RBCs)
|
|
what are bile salts important for?
|
emulsifying fat
|
|
where does the bile duct travel relative to the pancreas?
|
in or behind the head of pancreas
|
|
what lies anterior to the gallbladder fundus?
|
anterior abdominal wall
|
|
which two structures lie inferior to the gallbladder?
|
duodenum and transverse colon
|
|
why can gallbladder pain refer to the right shoulder region?
|
branches of the phrenic nerve innervate the gallbladder
|
|
what are the boundaries of Calot's triangle?
|
cystic duct
liver common hepatic duct |
|
where is the pancreas?
|
between duodenum and spleen
|
|
t/f... head of pancreas is higher than the tail
|
false, the head is lower than the tail
|
|
where do the superior mesenteric vessels lie relative to the pancreas?
|
superior mesenteric vessels pass anterior to the uncinate process of the pancreas
|
|
which part of the pancreas is in contact with the spleen?
|
tail
|
|
t/f... the pancreas is an intraperitoneal structure
|
false, it is retroperitoneal
|
|
where does the pancreatic duct begin?
|
tail of pancreas
|
|
where does the accessory pancreatic duct open?
|
minor duodenal papilla
|
|
what is a cause of jaundice involving the pancreas?
|
cancer of the head of the pancreas
|
|
where does the splenic artery travel relative to the pancreas?
|
on the superior border of the pancreas
|
|
where does the splenic vein travel relative to the pancreas?
|
posterior to pancreas
|
|
which vein is posterior to pancreas and below splenic vein?
|
left renal vein
|
|
which part of the pancreas is related to the lesser sac?
|
upper part
|
|
which part of the pancreas is related to the greater sac?
|
lower part
|
|
which part of the pancreas is not retroperitoneal?
|
tail (in splenorenal ligament)
|
|
where does pancreatic pain refer?
|
epigastrium
back |
|
what is the most easily ruptured structure in the abdominal cavity?
|
spleen
|
|
where is the spleen located?
|
left hypochondrium, posterior to midaxillary line, related to R9-11 (parallel to R10)
|
|
t/f... spleen is intraperitoneal
|
true
|
|
what are the three impressions on the visceral surface of the spleen?
|
gastric
renal colic |
|
which ligament contains the splenic vessels?
|
splenorenal ligament
|
|
which ligament contains the short gastric and gastroepiploic vessels?
|
gastrosplenic ligament
|
|
where is the root of the mesentery?
|
between the duodenojejunal junction and the ilioceacal junction
|
|
which of the jejunum and ileum is more vascular?
|
jejunum
|
|
what are Peyer's patches?
|
aggregated lymph follicles
|
|
which of the jejunum and ileum is associated with more numerous arterial arcades
|
ileum
|
|
which of the jejunum and ileum has longer vasa recta?
|
jejunum
|
|
which part of the small intestine is associated with more arterial arcades and shorter vasa recta?
|
ileum
|
|
which colic flexure is higher and more fixed?
|
left colic flexure
|
|
which is longer and narrower, the ascending or descending colon?
|
descending colon
|
|
which parts of the large intestine are mobile?
|
transverse and sigmoid
|
|
which three structures characterise the colon?
|
taeniae coli
haustrations appendices epiploica |
|
what holds the left colic flexure in position?
|
phrenocolic ligament
|
|
how does the rectum curve (looking anteriorly)?
|
right, left, right
|
|
where does the rectum start and end?
|
starts at SV3
ends at levator ani |
|
t/f... the rectum is entirely within the pelvic cavity
|
true
|
|
t/f... the upper 1/3 of rectum has peritoneum on front and sides
|
true
|
|
t/f... the lower 1/3 of rectum has peritoneum on its anterior surface
|
false, the middle 1/3 has peritoneum on its front but the lower 1/3 has no peritoneum
|
|
what are the anal valves?
|
mucous membranes joining lower ends of anal columns
|
|
what is the embryologic origin of the GIT below the pectinate line?
|
skin-derived (cf hindgut derived)
|
|
where do mucous glands open into the anus?
|
anal sinuses
|
|
what type of epithelium lines the anal canal above and below the pectinate line?
|
above - columnar epithelium
below - stratified squamous epithelium |
|
what is the blood supply to the anal canal above the pectinate line?
|
superior rectal artery (a branch of inferior mesenteric artery)
|
|
what is the blood supply to the anal canal below the pectinate line?
|
inferior rectal artery (branch of internal iliac artery)
|
|
what is the venous drainage of the anal canal above and below the pectinate line?
|
above - superior rectal vein -> portal vein
below - inferior rectal vein -> internal iliac vein |
|
what is the lymphatic drainage of the anal canal above the pectinate line?
|
pararectal lymph nodes along superior rectal artery (eventually to inferior mesenteric lymph nodes)
|
|
what is the lymphatic drainage of the anal canal below the pectinate line?
|
superficial inguinal lymph nodes
|
|
which anal sphincter is under voluntary control?
|
external sphincter
|
|
what is the true pelvis?
|
the pelvis between the pelvic inlet and outlet
|
|
what is the false pelvis?
|
pelvis above pelvic inlet to the top of iliac crest
|
|
t/f... the false pelvis is part of the abdominal cavity
|
true
|
|
what are the boundaries of the pelvic cavity?
|
pelvic inlet to pelvic diaphragm
|
|
what is the perineum?
|
region below pelvic diaphragm to skin of lower trunk
|
|
what shape is the pelvic inlet in males?
|
heart shaped
|
|
what separates the pelvic cavity from the perineum?
|
pelvic diaphragm
|
|
which pelvic opening is bony and ligamentous?
|
pelvic outlet
|
|
what is the widest orientation of the pelvic inlet?
|
transverse
|
|
what is the widest orientation of the pelvic outlet?
|
anterioposterior
|
|
what are the differences between the male and female bony pelvis?
|
male - heart shaped pelvic inlet, small pelvic outlet, true pelvis narrows, subpubic angle sharp
female - oval shaped pelvic inlet, large pelvic outlet, wide and parallel true pelvis, rounded subpubic angle |
|
the greater sciatic notch is broader in males or females?
|
females
|
|
which ligaments stabilise the sacroiliac joint?
|
sacrotuberous and sacrospinous ligaments
|
|
which muscle passes through the greater sciatic foramen?
|
piriformis
|
|
where does the pudendal nerve pass out of the pelvis?
|
greater sciatic foramen
|
|
where does the pudendal nerve pass to enter the perineum?
|
through the lesser sciatic foramen
|
|
what are the two parts of the pelvic diaphragm?
|
coccygeus
levator ani |
|
which part of levator ani is important in foecal continence?
|
puborectalis
|
|
what are the parts of levator ani?
|
pubococcygeus
puborectalis iliococcygeus |
|
where do both pubococcygeus and ileococcygeus attach?
|
levator plate
|
|
what lies immediately behind the pubic bone?
|
bladder
|
|
what lies immediately in front of the sacrum?
|
rectum
|
|
what are the peritoneal pouches in the pelvic cavity in males and females?
|
males - rectovesical
females - rectouterine (Pouch of Douglas) and uterovesical |
|
what are the two triangles that make up the diamond shaped perineum?
|
urogenital triangle and anal triangle
|
|
what are the contents of the anal triangle?
|
anal canal, anal sphincters, ischioanal fossa, pudendal canal
|
|
what are the two layers of the urogenital triangle?
|
perineal membrane (deep)
superficial perineal fascia |
|
where is the deep perineal pouch?
|
between pelvic diaphragm and perineal membrane
|
|
where is the superficial perineal pouch?
|
between perineal membrane and superficial fascia of perineum
|
|
what lies in front of the anal canal in both sexes?
|
perineal body
|
|
what is the main artery supplying the perineum?
|
internal pedundal artery
|
|
what is the main artery supplying the pelvic viscera?
|
internal iliac artery
|
|
what is the venous drainage of the pelvis and perineum?
|
valveless venous plexus -> internal iliac veins (some drainage to internal vertebral venous plexus via sacral veins)
|
|
what is the lymphatic drainage of the skin of the perineum?
|
superficial inguinal nodes
|
|
what innervates the pelvic viscera?
|
inferior hypogastric plexuses (lateral to pelvic viscera below peritoneum)
|
|
which nerve supplies the muscles of the perineum?
|
pudendal nerve
|
|
what is the parasympathetic supply to the pelvic viscera?
|
S2-4 via pelvic splanchnic nerves
|
|
pain afferents travel with which nerves is viscus is above the pelvic pain line?
|
sympathetics (T1-L2) - referred to dermatomes
|
|
pain afferents travel with which nerves if viscus is below pelvic pain line?
|
parasympathetics (S2-4)
|
|
where is the pelvic pain line?
|
halfway along sigmoid colon in GIT
lower limit of peritoneum |
|
what is the general function of epithelium?
|
separate inside world from outside world
|
|
what makes up the basolateral membrane?
|
basal membrane and lateral membrane
|
|
t/f... basal and lateral membranes are physiologically indistinguishable
|
true
|
|
which epithelial membrane contains the microvilli?
|
apical membrane
|
|
which epithelial membrane has higher concentrations of cholesterol?
|
apical membrane
|
|
where is the Na/K ATP-ase (sodium pump) found?
|
basolateral membrane
|
|
what are two functions of tight junctions?
|
cell-to-cell adhesion
barrier |
|
are tight junctions located closer to the apical or basal membrane?
|
apical
|
|
what is the intercellular space?
|
space between two lateral membranes of neighbouring cells
|
|
what is the direction of secretion?
|
inside world to outside world
|
|
what process occurs across epithelium from outside world to inside world?
|
absorption
|
|
what type of transport occurs between cells across tight junctions?
|
paracellular transport
|
|
what type of transport occurs through cells?
|
transcellular
|
|
what are the two types of transcellular transport?
|
active and passive
|
|
t/f... paracellular transport is always active
|
false, it is always passive
|
|
is water transport ever active?
|
usually passive following solute transport but some transporters move water and solute at the same time driven by the sodium gradient
|
|
what is the major mechanism by which water transport occurs in the gut?
|
NaCl absorption
|
|
what is the mechanism of NaCl absorption that occurs in villous cells in small intestine?
|
electroneutral
|
|
which two exchangers act as if they are coupled during electroneutral NaCl absorption?
|
Na/H exchanger
Cl/HCO3 exchanger |
|
what pushes the chloride out of the cell in electroneutral NaCl absorption?
|
HCO3 gradient out of the cell
|
|
why is electroneutral NaCl absorption called "electroneutral"?
|
there is no net movement of charge across the apical membrane
|
|
how does sodium cross the basolateral membrane?
|
sodium pump (3Na/2K)
|
|
how does chloride cross the basolateral membrane?
|
partially by KCl cotransport
partially by chloride channels |
|
where does electroneutral NaCl absorption occur?
|
from duodenum to halfway along colon
|
|
where does the electrogenic mechanism of NaCl absorption occur?
|
distal colon
|
|
how does sodium enter the cell in electrogenic NaCl absorption?
|
epithelial Na channels
|
|
how does sodium leave the cell in electrogenic NaCl absorption?
|
sodium pump
|
|
t/f... K is lost partially across the apical and partially across the basolateral membrane in electrogenic NaCl absorption
|
true
|
|
what drives the movement of chloride out of the lumen and K into the cell in electrogenic NaCl absorption?
|
the large negative charge generated by the movement of sodium out of the lumen
|
|
what drug blocks epithelial Na channels?
|
amiloride
|
|
which mechanism of NaCl absorption tends not to transport water?
|
electrogenic
|
|
what is the usual role of the NaK2Cl cotransporter?
|
volume control
|
|
what is the role of the NaK2Cl cotransporter in epithelial cells?
|
drive Na and Cl secretion
|
|
what keeps the sodium concentration inside the cell low?
|
NaKATPase
|
|
what keeps intracellular chloride high?
|
NaK2Cl cotransporter
|
|
what draws Na (and a bit of K) across the tight junctions in NaCl secretion?
|
the negative charge created by chloride exiting cells through Cl channels
|
|
t/f... tight junctions are selective for Na and K over Cl
|
true
|
|
what type of chloride channel is activated by protein kinase A?
|
CFTR channels (found in human crypts)
|
|
what type of chloride channel is activated by intracellular calcium?
|
Ca activated Cl channels (salivary, sweat glands)
|
|
where does NaHCO3 secretion occur?
|
bile ducts
pancreatic ducts duodenal mucosa |
|
t/f... intracellular concentration of HCO3 is high
|
true
|
|
which three proteins are used to maintain intracellular bicarb concentration?
|
NaH exchanger
NaHCO3 cotransporter H ATPase |
|
what is the role of SGLT1?
|
cotransports Na and glucose
|
|
t/f... GLUT2 is highly selective
|
false
|
|
t/f... SGLT1 is highly selective
|
true
|
|
does fructose enter cells actively or passively?
|
passively via GLUT5
|
|
what transports ACE inhibitors and cephalosporins?
|
PepT1
|
|
what does the PepT1 transporter transport?
|
proton and a peptide (di and tri amino acids)
|
|
what is wasting?
|
weight is 20% or more below ideal weight for height
|
|
what are the five basic mechanisms of failure to thrive?
|
inadequate intake
decreased absorption excessive losses abnormal utilisation increased need |
|
t/f... the yolk sac becomes part of the umbilical cord
|
true
|
|
t/f... the gut and its derivatives are derived from endoderm
|
true
|
|
which parts of the gut have a dorsal mesentery?
|
all parts
|
|
which parts of the gut have a ventral mesentery?
|
foregut only
|
|
what is mesentery?
|
double fold of mesoderm
|
|
which organs are foregut derived?
|
liver, gallbladder, pancreas
|
|
when does the stomach develop?
|
between the 4th and 8th week
|
|
which wall of the stomach grows faster?
|
dorsal wall
|
|
when does the stomach undergo a 90 degree rotation?
|
7th week
|
|
which mesentery does the liver develop in?
|
ventral mesentery
|
|
which structures of the GIT are initially retroperitoneal?
|
thoracic oesophagus
rectum |
|
which structures of the GIT are secondarily retroperitoneal?
|
duodenum
pancreas descending colon ascending colon |
|
when do the liver, gallbladder and pancreas develop?
|
4th to 6th week
|
|
t/f... the pancreas bud sprouts first
|
false, the liver bud sprouts first
|
|
what is the endodermal thickening that will form the gallbladder and cystic duct called?
|
cystic diverticulum
|
|
which viscus forms through the fusion of a ventral and dorsal bud?
|
pancreas
|
|
what does the dorsal pancreatic bud become?
|
uncinate process of pancreas
|
|
what is the effect of thyroid hormone on mitochondria?
|
increase size and number
|
|
what is the normal homeostatic range for blood glucose?
|
3-5 mmol/L
|
|
what hormone is stimulated by fasting to make nutrients available for cells?
|
glucagon (and other counter-regulatory hormones - cortisol, GH and adrenaline)
|
|
what stimulates insulin secretion?
|
increased glucose concentration
increased amino acid concentration food intake (-> GI hormones, parasympathetic stimulation) |
|
what is the major control of insulin release from the beta islet cells of the pancreas?
|
increased blood glucose concentration
|
|
which hormone/drugs inhibit the secretion of insulin?
|
somatostatin
phenytoin thiazide diuretics |
|
which organ is exposed to a higher concentration of insulin (and glucagon) than peripheral tissues?
|
liver (insulin released to portal circulation)
|
|
what are the effects of insulin on glucose?
|
increase uptake (especially by muscle, fat)
increase glycogen synthesis decrease glycogenolysis |
|
what are the effects of insulin on fat?
|
increase uptake (increase LDL receptor)
increased triglyceride inhibits lipolysis |
|
what are the effects of insulin on proteins?
|
increase amino acid uptake
increase protein synthesis decrease protein breakdown |
|
in which part of the brain is glucose transport insulin dependent?
|
satiety centre
|
|
where is glucose absorption insulin independent?
|
intestine
|
|
when is glucose uptake into muscle insulin independent?
|
during exercise
|
|
what stimulates release of counter regulatory hormones (to insulin)?
|
fasting
|
|
t/f... all the counter-regulatory hormones increase protein breakdown
|
false, growth hormone does not
|
|
which cells release glucagon?
|
alpha cells
|
|
what stimulates glucagon release?
|
decreased glucose
increased amino acids decreased fatty acids |
|
what are the effects of glucagon on carbohydrate?
|
increase glycogen breakdown
increase gluconeogenesis |
|
what is the effect of glucagon on protein?
|
protein breakdown (amino acids to liver for gluconeogenesis)
|
|
what are the effects of glucagon on fats?
|
lipolysis
ketogenesis (liver) |
|
what is the mechanism of blurred vision in diabetes?
|
hyperglycaemia and sorbitol accumulation
|
|
t/f... type 1 DM patients develop complications earlier than T2 patients
|
false, it is unusual for complications to be clinically significant in the first five years in T1 whereas complications may be present from diagnosis in T2
|
|
when do patients experience symptoms of diabetic retinopathy?
|
when there is macular involvement or if new vessels bleed
|
|
what are the two types of diabetic retinopathy?
|
non-proliferative
proliferative |
|
when will diabetic nephropathy be symptomatic?
|
when creatinine is much elevated
|
|
how are the early stages of diabetic nephropathy detected?
|
microalbuminuria and proteinuria
|
|
what is the first clinical sign of diabetic damage to the kidney?
|
microalbuminuria
|
|
what will help slow the progression of diabetic nephropathy in hypertensive diabetics?
|
effective antihypertensive treatment
|
|
what is seen histologically in diabetic nephropathy?
|
basement membrane thickening
deposition of matrix in glomerulus glomerular sclerosis |
|
what can artificially elevate microalbumin?
|
exercise
fever |
|
which antibodies might be present in T1DM?
|
islet cells
GAD (glutamic acid decarboxylase) IA2 insulin |
|
t/f... most patients with T1DM will have a positive family history
|
false
|
|
t/f... unsaturated fatty acids are liquids at body temperature
|
true
|
|
what comprises triglycerides?
|
glycerol + fatty acids
|
|
what is the major form of fat in diet and fat stores?
|
TAGs
|
|
what activates hormone-sensitive lipase?
|
adrenaline
glucagon |
|
what inhibits hormone-sensitive lipase?
|
insulin
|
|
t/f... insulin inhibits glucagon secretion
|
true
|
|
what is the primary effect of insulin on protein?
|
reduced proteolysis
|
|
what is the action of cortisol on muscle?
|
promotes proteolysis and transfer of amino acids to liver
promotes conversion of amino acids to glucose |
|
what is the effect of insulin on fatty acids after hepatic uptake in DKA?
|
insulin blocks transfer of fatty acids into mitochondrial matrix
|
|
what biochemical change will be present early in DKA?
|
high potassium early (but intracellular K depletion)
|
|
t/f... low GI meals reduce postprandial insulin
|
true
|
|
t/f... low GI diets improve insulin sensitivity
|
true
|
|
will a meal that is slowly digested induce more or less satiety than a meal that is rapidly digested?
|
more satiety
|
|
what type of diet helps prevent T2DM?
|
low fat
|
|
which type of carbs improve glycaemic control?
|
low GI
|
|
which type of diet improves lipids?
|
mediterranean-style diets
|
|
which primary pathogens are associated with cellulitis?
|
S. pyogenes
S. aureus |
|
where are insulin receptors found?
|
hepatocytes
skeletal muscle fat cells |
|
which IRS isoforms are major mediators of insulin action?
|
IRS 1
IRS 2 |
|
how can insulin resistance be reversed?
|
weight loss and exercise
|
|
what do adipocytes release at extreme TAG levels?
|
monocyte chemotactic protein-1
|
|
what do adipose macrophages release?
|
TNF alpha
|
|
what is the effect of TNF alpha on PPARgamma function in fat?
|
suppression
|
|
what is the role of PPARgamma modulators in fat and muscle?
|
upregulate insulin sensitivity
|
|
what do PPARs respond to?
|
eicosanoids and in some cases FAs
|
|
what are the therapeutic PPARgamma modulators?
|
thiazolidinediones (e.g. rosiglitazone)
|
|
what triggers release of ADH from posterior pituitary?
|
serum osmolality
|
|
what are the two types of diabetes insipidus and the differences between them?
|
cranial DI - failure of ADH secretion by posterior pituitary
nephrogenic DI - resistance to action of ADH at kidney |
|
what are the phenotypic features of pseudohypoparathyroidism?
|
short stature
shortened metacarpals/metatarsals deformities of hands and feet |
|
what are the features of metabolic syndrome?
|
insulin resistance or T2DM
central obesity hypertension dyslipidaemia atherosclerosis and CV disease |
|
what are the two theories explaining insulin deficiency in T2DM?
|
glucose toxicity
amylin |
|
what are the monozygotic twin concordance rates for both types of diabetes?
|
T1 - 15-50%
T2 - >90% |
|
what percentage of diabetes is caused by a single gene defect?
|
1-2%
|
|
what deformity is associated with diabetic foot disease?
|
Charcot's joint
|
|
what is the treatment for hyperosmolar coma?
|
rehydration
careful infusion of insulin potassium |
|
which oral hypoglycamics increase insulin release?
|
sulfonylureas
insulin secretagogues |
|
which oral hypoglycaemics increase insulin sensitivity?
|
biguinides (metformin)
thiozoladinediones |
|
which oral hypoglycaemic decreases sugar absorption from gut?
|
acarbose
|
|
what is a normal HbA1c?
|
3.5-6%
|
|
what is the BSL for a hypo?
|
<3.7
|
|
what percentage of genetic contribution is associated with obesity?
|
30-70%
|
|
which lipoproteins are the largest?
|
chylomicrons
|
|
which apoprotein on chylomicrons promotes LPL activity?
|
Apo CII
|
|
what converts chylomicrons to chylomicron remnants?
|
action of lipoprotein lipase (depletes TAGs)
|
|
where are VLDLs synthesised?
|
liver
|
|
what happens to VLDL remnants?
|
taken up by liver or converted to LDL in circulation
|
|
familial hypercholesterolaemia is associated with deficiency of what?
|
LDL receptors
|
|
how do statins lower LDL levels?
|
suppress cholesterol synthesis (esp. in liver)
hepatocytes - increased expression of LDL receptors LDLs taken up from plasma |
|
what are the statins?
|
HMG CoA reductase inhibitors
|
|
what does HMG CoA reductase do?
|
catalyses a key step in cholesterol synthesis
|
|
what is the effect of diabetes on VLDLs?
|
elevated VLDLs resulting in increased serum TAGs
|
|
what is the effect of diabetes on lipoprotein lipase activity?
|
reduced activity
|
|
what is the mechanism of action of fibrates?
|
activate PPARalpha (suppresses VLDL production, enhances activity of LPL, TAGs fall)
|
|
what percentage of anterior pituitary cells are corticotrophs?
|
20%
|
|
which zone of the adrenal gland secretes mineralocorticoids?
|
zona glomerulosa
|
|
which zones of the adrenal cortex secrete glucocorticoids and androgens?
|
zona fasciculata
zona reticularis |
|
t/f... cortisol has a maximum output beyond which higher concentrations will not be achieved despite ACTH
|
true
|
|
what are the effects of cortisol on carbohydrate metabolism?
|
gluconeogenesis
reduces rate of glucose utilisation by cells increased glucose in blood |
|
what are the effects of cortisol on protein metabolism?
|
reduced protein in cells (except for liver where protein is increased)
|
|
what is the effect of cortisol on fat metabolism?
|
increased lipolysis (in presence of GH and ACTH)
|
|
what are the pharmacological actions of cortisol?
|
anti-inflammatory
immunity |
|
what stimulates secretion of cortisol?
|
hypoglycaemia
emotional stresses drive for diurnal rhythm trauma |
|
which happen first in glucocorticoid excess, tissue or metabolic changes?
|
metabolic changes
|
|
what is the rate limiting step in steroid synthesis?
|
conversion of cholesterol to pregnenolone
|
|
how is cortisol transported in plasma?
|
bound to cortisol binding globulin (transcortin) and albumin
|
|
which steroid has the highest glucocorticoid activity?
|
dexamethasone
|
|
what is inflammation of
a) small bowel b) large bowel c) gall bladder? |
a) Crohn's disease
b) ulcerative colitis c) cholecystitis |
|
how will the pancreas appear on CT/MRI if there is
a) acute inflammation b) chronic inflammation? |
a) swollen
b) shrunken |
|
what might a mass at the head of pancreas obstruct?
|
bile duct
|
|
what other organ might be affected by a mass at the tail of the pancreas?
|
spleen
|
|
what is the normal span of a spleen?
|
11+/-2cm
|
|
what is the endocrine component of the pancreas?
|
islets of Langerhans
|
|
which hormones are secreted by the islets of Langerhans?
|
insulin
glucagon somatostatin |
|
what percentage of the weight of the pancreas is made up of islets of Langerhans?
|
2%
|
|
what percentage of the weight of the pancreas is made up of the exocrine component?
|
96%
|
|
how much pancreatic juice does the exocrine pancreas produce each day?
|
approx 2L
|
|
what do the pancreatic acini secrete?
|
isotonic NaCl rich fluid and a wide range of proteins
|
|
what are the precursors of digestive enzymes called?
|
zymogens
|
|
where are the zymogens normally acivated?
|
gut lumen
|
|
what activates zymogens in the gut lumen?
|
activation of trypsinogen by enteropeptidase (a brush border protease)
|
|
t/f... colipase is an enzyme
|
false, it is a cofactor required for efficient binding of pancreatic lipase to micelles
|
|
how is colipase secreted?
|
as a precursor - procolipase
|
|
what does pancreatic secretory trypsin inhibitor (PSTI) do?
|
prevents premature activation of zymogens by any active trypsin formed prior to their secretion
|
|
what is required for maximal activity of pancreatic lipase in hydrolysing triglycerides?
|
colipase
|
|
what stimulates pancreatic acinar fluid and electrolyte secretion?
|
cholecystokinin and acetylcholine
|
|
how do both cholecystekinin and acetylcholine act?
|
by increasing intracellular free calcium
|
|
what is secreted by pancreatic ducts?
|
NaHCO3 rich fluid and low amounts of mucoprotein
|
|
what stimulates the secretion of NaHCO3 by pancreatic ducts?
|
secretin
|
|
how does secretin act?
|
increasing intracellular cAMP
|
|
malabsorption of which nutrient will occur first?
|
fat
|
|
fat malabsorption does not occur until lipase and colipase secretion are less than ... of average normal values?
|
2%
|
|
at what pH is pancreatic lipase active?
|
alkaline pH
|
|
why does failure of bicarb secretion (e.g. in CF) exacerbate fat malabsorption?
|
pancreatic lipase is strongly pH sensitive and is only active at alkaline pH
|
|
name some congenital conditions in which protein malabsorption can occur due to pancreatic insufficiency
|
CF
Schwachman syndrome (congenital hypoplasia of the pancreas) congenital trypsinogen deficiency |
|
t/f... fat digestion is impaired in coeliac disease
|
false, fat digestion is unimpaired but there is impairment of absorption of products of digestion, fatty acids and monoglycerides
|
|
what are the major carbohydrates that can be digested by humans?
|
starch
disaccharides monosaccharides |
|
what do salivary and pancreatic amylase do?
|
attack starch by attacking linear chains of at least 6 glucose moieties linked by alpha-1,4 bonds
|
|
what inactivates salivary amylase?
|
low pH in stomach
|
|
what is released when pancreatic amylase attacks starch?
|
maltose
maltotriose alpha-limit dextrins (contain alpha-1,6 bonds that cannot be attacked by amylase) |
|
which digestive enzyme cleaves alpha-1,4 bonds to release glucose?
|
glucoamylase
|
|
which digestive enzyme cleaves alpha-1,6 bonds and glucose-alpha-1,2-fructose bonds?
|
sucrase-isomaltase
|
|
what does lactase break down?
|
glucose-beta-1,4-galactose bonds to break down lactose
|
|
what are the small intestine brush border enzymes involved in the digestion of carbohydrates?
|
glucoamylase
sucrase-isomaltase lactase and others |
|
what happens to dietary fibre?
|
reaches the large bowel intact
fermented by colon microflora releasing short chain fatty acids and gases |
|
what is the initial enzyme involved in the digestion of protein?
|
pepsin
|
|
what secretes the endopeptidase pepsin?
|
chief cells of the gastric mucosa
|
|
what is the inactive precursor of pepsin?
|
pepsinogen
|
|
what activates pepsinogen?
|
low pH (<3)
|
|
what degrades proteins to oligopeptides in the small intestine?
|
exopeptidases and endopeptidases
|
|
when are exopeptidases and endopeptidases activated?
|
when they reach the duodenal lumen
|
|
what activates trypsinogen?
|
brush border enzyme enteropeptidase
|
|
what activates most of the proenzymes in the duodenal lumen involved in protein digestion?
|
trypsin
|
|
what degrades oligopeptides to their constituent amino acids?
|
brush border enzymes including endopeptidases, aminopeptidases, carboxypeptidases and dipeptidases
|
|
t/f... oligopeptides are either fully degraded by brush border enzymes or transported into enterocytes and then degraded to amino acids
|
true
|
|
what secretes bile salts?
|
liver
|
|
what is required for the formation of micelles?
|
presence of bile salts
|
|
the formation of what is required for digestion of lipids?
|
micelles
|
|
where do micelles form?
|
lumen of small intestine
|
|
what breaks down triglycerides?
|
pancreatic lipase in the presence of colipase
|
|
what is released when trigylcerides are broken down?
|
2-monoacylglycerol and fatty acids
|
|
how are cholesterol esters digested?
|
hydrolysed by pancreatic enzyme cholesterol esterase
|
|
what breaks down phospholipids?
|
phospholipase A2
|
|
what is released when phospholipids are broken down?
|
fatty acids and lysophospholipids
|
|
what transports glucose and galactose across the apical membrane of small intestinal villous cells?
|
sodium glucose cotransporter SGLT1
|
|
what transports fructose across the apical membrane of small intestinal villous cells?
|
GLUT5
|
|
t/f... fructose transport across the apical membrane is active
|
false, it is passive
|
|
what transports the monosaccharides out of the small intestinal villous cells?
|
GLUT2
|
|
where are monsaccharides metabolised?
|
liver
|
|
what are the products of carbohydrate digestion?
|
glucose (80%)
fructose (14%) galactose (5%) |
|
what are the products of protein digestion?
|
di- and tri-peptides and amino acids
|
|
in general, the transporters for which amino acids are Na-coupled?
|
acidic and dipolar amino acids
|
|
which amino acids are associated with transporters that are not sodium-coupled?
|
basic amino acids
|
|
what transports small peptides across the apical membrane of small intestinal villous cells?
|
a variety of secondary active transporters that cotransport them with H
|
|
what happens to peptides inside small intestinal villous cells?
|
peptides are broken down by cytosolic hydrolases to amino acids
|
|
what transmits amino acids to the liver?
|
portal vein
|
|
what are the products of triglyceride digestion?
|
monoglyceride and two fatty acids
|
|
what is the role of micelles in triglyceride absorption?
|
maintain the concentration of MG and FA in the unstirred aqueous fluid layer in contact with apical membrane
|
|
what happens to monoglyceride and long chain fatty acids in the enterocyte?
|
they are resynthesised in the er into triglycerides and bound to specific apolipoproteins to form chylomicrons which are then secreted and enter the lymphatics
|
|
what happens to medium chain fatty acids following absorption?
|
transported to liver via portal circulation
|
|
how does cholesterol cross the apical membrane?
|
specific carrier protein
|
|
what happens to cholesterol in the enterocyte?
|
re-esterified and secreted as a cholesterol ester into lymphatics
|
|
what are the products of phospholipid digestion?
|
FA
lyso-phospholipids |
|
what happens to lyso-phospholipid in the enterocyte?
|
some is used to reform phospholipids which are incorporated into chylomicrons and VLDLs
remainder is broken down to water soluble metabolites and transported to liver via portal circulation |
|
which grains should be avoided on a gluten free diet?
|
wheat
barley rye |
|
what structure will perform jejunal functions following resection of the jejunum?
|
ileum
|
|
what is generally expected if more than 100cm of ileum is removed?
|
malabsorption
|
|
t/f... feeding is not recommended in the case of a true small bowel obstruction
|
true
|
|
how is thiamine absorbed in the small intestine?
|
active sodium and energy dependent carrier mechanism or by passive diffusion
|
|
where are riboflavin and the flavine nucleotides absorbed?
|
proximal jejunum
|
|
how are riboflavin and the flavine nucleotides absorbed?
|
saturable transport system following release from food proteins by gastric acidification
|
|
t/f... B-6 undergoes dephosphorylation before absorption
|
true
|
|
where are niacin and B-6 assimilated?
|
jejunum
|
|
how are niacin and B-6 assimilated?
|
facilitated and/or passive diffusion
|
|
how happens to ascorbic acid before it is transported across the enterocyte membrane by an energy dependent process?
|
undergoes conversion to the dihydro derivative
|
|
which two vitamins have specific intestinal transport mechanisms?
|
B-12 and folate
|
|
describe the steps leading up to the absorption of vitamin B-12 in the ileum
|
B-12 is freed from food linkages by gastric acid and then binds to salivary R polypeptides.
the R polypeptides are hydrolysed from B-12 by pancreatic proteases, enabling B-12 to bind to IF secreted from gastric parietal cells which bond to specific ileal receptors where B-12 is absorbed |
|
what transports B-12 through the mucosal cell?
|
carrier protein - transcobalamin II
|
|
what process is required before folate can be absorbed?
|
cleavage from polyglutamates in food by upper jejunal brush border conjugases
|
|
in what situations is conjugase action impaired?
|
coeliac disease
drug exposure (salazopyrine, dilantin, alcohol) |
|
how are fat soluble vitamins absorbed?
|
incorporated in bile salt micelles in upper jejunum
|
|
which fat soluble vitamins require prior hydrolysis to enhance their absorption?
|
retinyl esters
|
|
which fat soluble vitamin requires both bile and pancreatic enzymes for absorption?
|
Vitamin K
|
|
how are most trace metals absorbed?
|
passive diffusion
|
|
in what form is iron absorbed?
|
ferrous
|
|
how is ferrous iron absorbed?
|
via brush border of upper SI cells: it bonds to a membrane receptor protein and absorption may be facilitated by a cytosolic apotransferrin
|
|
which foods impair iron absorption?
|
milk protein, tea, coffee, phytates
|
|
what is lactose?
|
disaccharide found in mammalian milk
|
|
t/f... lactose is absorbed by small bowel after it is hydrolysed into galactose and glucose
|
true
|
|
what catalyses the hydrolysis of lactose?
|
lactase
|
|
where is lactase expressed?
|
in brush border of small intestinal (especially jejunal) villous epithelial cells
|
|
what does maltase act on?
|
maltose
maltotriose |
|
what does sucrase act on?
|
sucrose
|
|
what does isomaltase act on?
|
branched chain units of glucose derived by the action of alpha-amylase on glycogen or amylopectin
|
|
what is maltose?
|
glucose-glucose (alpha-1,4 linkage)
|
|
what is maltotriose?
|
glucose trisaccharide (alpha-1,4 linkage)
|
|
what is starch?
|
straight chain alpha-1,4 polymer of glucose
|
|
what breaks down starch?
|
salivary and pancreatic alpha-amylase
|
|
what happens to lactose in the colon?
|
lactose is metabolised by bacteria yielding hydrogen gas
|
|
what are the symptoms of lactose malabsorption?
|
abdominal pain
abdominal distension increased flatus audible borborygmi watery diarrhoea |
|
what is the mechanism of the symptoms of lactose malabsorption?
|
osmotic effect of unabsorbed lactose and fermentation of unabsorbed carbohydrates by colonic bacteria
|
|
t/f... malabsorption of carbohydrates diminishes the nutritional value of milk
|
true
|
|
what is the result of severe lactose intolerance in infants?
|
failure to thrive
|
|
describe the stool of lactose malabsorption
|
watery
acidic contain reducing substances |
|
what is the osmotic gap of osmotic diarrhoea?
|
100 or more
|
|
what is the osmotic gap of secretory diarrhoea?
|
less than 50
|
|
how is stool osmotic gap calculated?
|
stool osmolality minus 2x(stool Na+stool K)
|
|
which infants are unable to digest lactose in breast milk?
|
those with congenital lactase deficiency
|
|
in what percentage of the world's population does lactase activity persist into adult life?
|
30%
|
|
what will a small intestinal biopsy show in non-persistence of lactase?
|
normal except for low levels of lactase (normal levels of other disaccharidases)
|
|
t/f... secondary lactase deficiency is irreversible
|
false, it is usually a transient and reversible disorder
|
|
name one of the most common causes of secondary lactase deficiency and lactose intolerance in children
|
viral gastroenteritis
|
|
where is lymphoid tissue found in the gastrointestinal, respiratory and genitourinary tracts?
|
lamina propria and submucosa
|
|
how is lymphoid tissue arranged in the bronchi?
|
diffuse lymphoid aggregates
|
|
which cells are present in respiratory epithelium for processing of antigens?
|
dendritic cells
|
|
how is lymphoid tissue arranged in the lamina propria of the intestinal wall?
|
diffuse accumulations
|
|
where are Peyer's patches?
|
lower ileum
|
|
humoral immune response at the mucosal level are mostly of which isotype?
|
IgA
|
|
what is actively transported across mucosal membranes to heplp prevent entry or infectious organisms?
|
IgA
|
|
what protects secretory IgA from proteolytic digestion in the gut lumen?
|
presence of secretory component
|
|
how do IgA dimers secreted by submucosal cells reach the gut lumen?
|
bind to poly-Ig receptors on internal surface of epithelial cells
the complex is then endocytosed and transported across the cell to fuse with plasma membrane at luminal surface receptor is then cleaved, releasing IgA dimers bound to secretory component |
|
what type of lymphocytes are present in the lamina propria?
|
activated T cells
activated B cells plasma cells |
|
what type of lymphocytes are present in the epithelial layer?
|
CD8 T cells
|
|
what synthesises secretory component?
|
intestinal epithelial cells
|
|
t/f... MALT consists of encapsulated lymphoid tissue
|
false, it consists of non-encapsulated lymphoid tissue
|
|
what do microfold cells in the epithelium of the small intestine do?
|
transport antigens from the gut to Peyer's patches
|
|
what is the function of poly-Ig receptors on gut epithelial cells?
|
to bind IgA dimers and transport them to the gut lumen
|
|
what damage to the small intestine occurs in Coeliac disease?
|
villous atrophy
crypt hyperplasia |
|
which two HLA types are associated with Coeliac disease?
|
HLA-DQ2 and HLA-DQ8
|
|
what fraction of people with HLA types DQ2 or 8 develop CD?
|
1 in 30
|
|
which enzyme deamidates gluten peptides in the enterocyte?
|
tissue transglutaminase
|
|
what is the prevalence of CD?
|
1:250 to 1:75
|
|
what is the classical presentation of CD in childhood?
|
toddler presents with anorexia, diarrhoea, irritability, malnourished, pallor, buttock wasting, pot-bellied appearance
|
|
what percentage of toddlers presenting with CD have clubbing?
|
30%
|
|
what percentage of toddlers presenting with CD have constipation?
|
20%
|
|
which deficiencies are common in toddlers presenting with CD?
|
iron and folate
|
|
in what percentage of first degree relatives is asymptomatic CD found?
|
33%
|
|
how is CD diagnosed?
|
small bowel biopsy demonstrating subtotal villous atrophy and crypt hyperplasia
|
|
what is the most sensitive and specific test for CD?
|
IgA antiendomyseal antibodies against reticulin in monkey oesophageal smooth muscle
|
|
what is the sensitivity and specificity of IgA tissue transglutaminase antibodies?
|
sensitivity - 92%
specificity - 98% |
|
how is CD treated?
|
gluten free diet
|
|
what are the possible consequences of persistent non-compliance with gluten free diet in CD?
|
small bowel malignancy
higher incidence of autoimmune disease |
|
t/f...most cases of CD will present with fat malabsorption
|
false
|
|
t/f... the anaemia that occurs in CD is most commonly due to B-12 deficiency
|
false, it is due to iron and/or folate deficiency
|
|
what is the mechanism of small intestinal injury in viral infections?
|
virus particles invade mature enterocytes and cause them to desquamate
|
|
what do crypt cells do in the case of rotavirus?
|
crypt cells (not infected by virus) proliferate and cover the injured villus but fail to differentiate normally
|
|
what happens to villi when covered with crypt cells for defence against viral invasion?
|
the villus becomes covered with immature cells which lack the normal brush border enzymes such as lactase and SGLT1
|
|
what type of diarrhoea occurs with malabsorption?
|
osmotic diarrhoea
|
|
what may induce abnormal secretion of water and electrolytes resulting in secretory diarrhoea?
|
bacterial toxins in the gut lumen e.g. heat labile toxin of Vibrio cholera and the heat stable toxin of enterotoxigenic E coli
|
|
how do bacterial toxins stimulate chloride secretion from enterocytes?
|
a) altering cell regulation events in enterocytes
b) modulating enteric nerves and enteroendocrine cells which have a role in modulating secretion |
|
t/f... intestinal secretion can be stimulated by immunocytes in the mucosa/lamina propria
|
true
|
|
how does rotavirus stimulate enterocyte secretion?
|
produces a capsid protein that alters intracellular calcium levels
|
|
t/f... mast cell degranulation induces profuse secretion
|
true
|
|
what is the major mechanism for expulsion of intestinal helminths?
|
mast cell degranulation
|
|
which inflammatory mediators are released by neutrophils in the gut that induce water secretion?
|
arachadonic acid metabolites
TNF 5'-AMP |
|
which cells in the mucosa produce secretagogues?
|
fibroblasts
endothelial cells lymphocytes macrophages |
|
what are the main phagocytes in the gut?
|
neutrophils
|
|
which products of maldigestion can stimulate colonic secretion?
|
dihydroxy fatty acids
|
|
t/f... infectious gastroenteritis is usually associated with steatorrhoea
|
false
|
|
what contributes to the abdominal pain frequently associated with gastroenteritis?
|
altered motility
|
|
what disturbance of motor activity occurs with intestinal anaphylaxis?
|
rapidly migrating high pressure peristaltic waves which move aborally
|
|
t/f... cholera does not inhibit the glucose coupled sodium transporter in the small intestine
|
true
|
|
how does cholera stimulate secretion in enterocytes?
|
via a cAMP mediated chloride channel
|
|
how much fluid enters the GIT of a normal adult per day?
|
9L (2L ingested, 7L endogenous and electrolytes)
|
|
what comprises endogenous fluid and electrolytes entering the GIT?
|
salivary, gastric secretions, bile, pancreatic secretions, endogenous small intestinal secretion
|
|
how much fluid enters the colon per day?
|
1.5L
|
|
how much fluid exits the GIT in stool per day?
|
0.1-0.2L
|
|
what increase in stool volume occurs with diarrhoea?
|
>0.1L
|
|
what are the 4 major cell populations arising from intestinal epithelium?
|
enterocytes
paneth cells goblet cells enteroendocrine cells |
|
which layer lies beneath the intestinal epithelium?
|
lamina propria
|
|
what is the pH of the small bowel?
|
8
|
|
what is the pH of the stomach?
|
2
|
|
what protects the small bowel from bacterial invasion?
|
low pH
|
|
what protects the colon from bacterial invasion?
|
normal flora (compete with pathogens for adherence to mucosal surface)
|
|
t/f... fever is slight or absent in food poisoning
|
true
|
|
food poisoning with which pathogen does not have a rapid onset of diarrhoea and vomiting?
|
botulism (takes 12-18 hours to produce paralysis)
|
|
which pathogen is responsible for food poisoning of egg dishes?
|
staph aureus
|
|
which foods are at danger of food poisoning with clostridium perfringens when reheated?
|
meat and gravy
|
|
what is the pathogen associated with rice food poisoning?
|
bacillus cereus
|
|
how does staph aureus cause food poisoning?
|
enterotoxins (proteins) secreted by Staph aureus
resist hydrolysis by gastric and jejunal enzymes are stable to 100 degrees for 30 minutes strong inducers of cytokine formation esp IL-1 |
|
which cytokine is strongly induced by enterotoxins of S aureus?
|
IL-1
|
|
how do enterotoxins of staph aureus cause nausea and vomiting?
|
peripheral stimulation of vomiting centre
|
|
when do symptoms occur following ingestion of enterotoxins of staph aureus?
|
within 1-6 hours of ingestion
|
|
how long do symptoms of food poisoning with staph aureus last?
|
less than 12 hours
|
|
what is the origin of clostridium perfringens?
|
animal faeces
|
|
what is the incubation period of clostridium perfringens?
|
8-14 hours
|
|
what are the two forms of bacillus cereus?
|
emetic (staph aureus like) and diarrhoeal (clostridial)
|
|
list some non-microbial causes of food poisoning?
|
heavy metals
mutant zucchinis reef fish (ciguatera poisoning) mushrooms blue-green algae methanol |
|
which mushroom can cause fatal hepatotoxicity?
|
amanita phylloides (death cap)
|
|
what are ciguatoxins?
|
heat-stable, lipid-soluble polyethers which accumulates in the muscles of tropical fish
|
|
what are the symptoms of ciguatera poisoning?
|
begins with vomiting, diarrhoea, abdominal pain
followed by parasthesia, dysthesia, myalgia, muscle cramps and weakness |
|
when may neurological symptoms of ciguatera poison recur?
|
during exercise or alcohol comsumption
|
|
which blood group is associated with greater risk of cholera, EHEC and norovirus infections?
|
O (receptor for the pathogens)
|
|
what age group gets rotaviruses?
|
infants
|
|
why does lactose intolerance develop with viral diarrhoea?
|
infected cells are damaged and lost leaving immature cells with reduced absorptive capacity and lack of disaccharidases
|
|
how do viruses cause diarrhoea?
|
ingested virus infects cells at top of villi in small intestine
spreads to infect large numbers of these cells release of virus particles into lumen infected cells are damaged and lost leaving immature cells with reduced absorptive capacity fluid accumulation in lumen diarrhoea and dehydration |
|
when does rotavirus become very common?
|
post-weaning
|
|
what is the incubation period of Norwalk virus infection?
|
24--48 hours
|
|
what is the duration of illness of Norwalk virus infection?
|
12-60 hours
|
|
where do outbreaks of norovirus occur?
|
in closed communities (cruise ships, barracks, nursing homes)
|
|
what are the two types of bacterial enteritis?
|
enterotoxic
enteroinvasive |
|
what are the two major enterotoxigenic bacteria?
|
cholera
E coli |
|
what are the features of toxigenic diarrhoea?
|
watery, profuse diarrhoea
fever low or absent no foecal leucocytes |
|
descibe the cholera organism
|
gram negative curve rods with a single flagellum on one end
|
|
where do cholera toxins adhere?
|
proximal small bowel cells
|
|
t/f... cholera toxins adhere to small bowel cells and then enter the cells
|
false, they do not enter cells
|
|
which component of the cholera toxin attaches to the cell receptor?
|
B component
|
|
which receptor does cholera bind to?
|
GM1 - ganglioside receptor
|
|
what activates adenyl cyclase in cholera infection?
|
A1 subunit of cholera toxin
|
|
where does cAMP accumulate in cholera infection?
|
along the cell membrane
|
|
what does the accumulation of cAMP along the cell membrane do in cholera infection?
|
causes active secretion of sodium, chloride, potassium, bicarbonate and water into the intestinal lumen
|
|
where do enteroinvasive bacteria invade the bowel?
|
distal small bowel
|
|
what are the classic organisms causing invasive diarrhoea?
|
campylobacter
salmonella yersinia |
|
what are the features of invasive diarrhoea?
|
moderate stool volume
fever colicky abdominal pain foecal leucocytes |
|
what are the two commonest causes of protozoan enteropathy?
|
giardia intestinalis
cryptosporidium parvum |
|
which patients may get relapsing infections of giardia?
|
patients with IgA deficiency
|
|
which patients experience persistent infection with cryptosporidium parvum?
|
patients with AIDS
|
|
which form of giardia survives chlorination and heating?
|
cyst form
|
|
what is the main function of the intestinal mucosa?
|
transport of water, electrolytes, nutrients and other substances important for maintaining mucosal integrity
|
|
how is water absorbed in the GIT?
|
paracellularly and transcellularly
|
|
how are ions and other small molecular weight solutes absorbed?
|
passively through the paracellular pathway
dissolved in water transcellularly via specific ion transporters |
|
what is the main basolateral transporter creating the internal concentration and electrical gradients to facilitate ion transport?
|
basolateral Na/K ATPase
|
|
where is K absorbed passively?
|
small intestine
|
|
where is K absorbed actively and secreted?
|
colon
|
|
what happens to undigested carbohydrate in the colon?
|
fermented to short chain fatty acids by colonic bacteria and then absorbed coupled to Na or via anion exchangers
|
|
how is secretion of fluid by the intestinal epithelium facilitated?
|
apical secretion of Cl via specific Cl channels
|
|
what happens to Na absorption when Cl secretion is stimulated?
|
Na absorption is inhibited
|
|
which biochemical abnormalities indicate dehydration?
|
high urea and creatinine
|
|
which biochemical abnormalities indicate depleted intravascular volume?
|
matabolic acidosis (low pH, low HCO3)
|
|
which biochemical abnormalities may indicate chronic diarrhoea?
|
low potassium and magnesium
|
|
t/f... the acidosis associated with acute diarrhoea is usually corrected with rehydration and bicarbonate therapy
|
false, bicarbonate therapy is rarely required
|
|
what can cause watery (osmotic) diarrhoea?
|
malabsorption (or excessive ingestion) or osmotically active substances such as carbohydrate
diseases that damage the small intestinal mucosa (e.g. viral gastroenteritis, some bacterial and parasitic infections) |
|
what is the cause of mucosal damage in regions where malnutrition is endemic?
|
tropical enteropathy
infestation with parasites and pathogenic bacteria nutritional deficiencies such as zinc and vitamin A |
|
what is the most common cause of watery (secretory) diarrhoea?
|
infection e.g. cholera
|
|
what type of chloride secretion occurs with cholera?
|
electrogenic
|
|
what is the commonest cause of travellers diarrhoea?
|
E coli
|
|
t/f... mast cell degranulation can cause excessive intestinal secretion
|
true
|
|
t/f... intestinal inflammation does not cause excessive intestinal secretion
|
false
|
|
what are the causes of steatorrhoea?
|
inadequate bile salt concentration
reduced pancreatic lipase secretion (e.g. CF) damage to mucosal surface abnormal chylomicron formation blocked intestinal lymphatics |
|
what are the features of the stool in colonic inflammation?
|
bloody stools
excessive white cells |
|
what are the causes of bloody stools?
|
bacterial infection
food allergies viral infections in immunosuppressed individuals chronic inflammatory bowel disease |
|
t/f... diarrhoea usually occurs via a single mechanism
|
false, diarrhoea usually results from a complex interplay of many factors
|
|
what are the three gastrointestinal processes required for digestion?
|
gut motility
absorption secretion |
|
where do phasic contractions occur in the GIT?
|
small intestine
|
|
where do tonic contractions occur in the GIT?
|
gastric fundus
colon (particularly sigmoid) |
|
t/f... the ileocaecal valve prevents contents in the caecum from reluxing into ileum
|
true
|
|
which motor functions are important in the oesophagus?
|
propulsion
|
|
which motor functions are important in the stomach?
|
temporary storage
mixing propulsion |
|
which motor functions are important in the small intestine?
|
propulsion
mixing some storage |
|
which motor functions are important in the colon?
|
propulsion
mixing storage |
|
which pattern of digestive tract motility is a response to swallowing?
|
primary peristalsis
|
|
which pattern of digestive tract motility is a response to unconscious swallowing or reflux?
|
secondary peristalsis
|
|
which patterns of digestive tract motility occur in the proximal stomach?
|
proximal stomach: tonic receptive relaxation to accomodate food; subsequent tonic contraction to facilitate emptying
|
|
which pattern of digestive tract motility occur in the distal stomach?
|
phasic antral contractions (grind and empty contents)
|
|
what size are the particles ground by the antral pump?
|
0.5-1.5mm
|
|
what are the two functional motor regions of the stomach?
|
gastric reservoir
antral pump |
|
what are the patterns of digestive tract motility in the small intestine?
|
interdigestive motor activity (migrating motor complex)
degestive motor pattern (irregular mixing contractions) |
|
where does the migrating motor complex occur?
|
stomach and small intestine
|
|
what are the patterns of digestive tract motility in the colon and ano-rectum?
|
phasic and tonic contractions (mixing and propulsion)
gastro-colic reflex (increased contractile activity after eating defaecation |
|
t/f... in the colon, non-propogating contractions increase during sleep and decrease on waking
|
false, the opposite is true
|
|
when are high amplitude propogated contractions triggered in the colon?
|
waking from sleep
prior to defaecation |
|
using the barsotat technique, what does a decreased balloon volume indicate?
|
increased colonic tone
|
|
what is the role of the MMC in the small bowel during fasting?
|
prevents stasis and bacterial overgrowth
|
|
what is the fed pattern of the small bowel?
|
irregular mixing contractions
|
|
what percentage increase is there in colonic tone following a meal?
|
30%
|
|
which components of the GIT are under conscious influence?
|
mouth
upper oesophageal sphincter striated muscle of proximal oesophagus anus |
|
what controls gut motility?
|
autonomic nervous system
enteric nervous system |
|
what is the enteric nerve system?
|
network of cells in gut wall comprising the myenteric plexus (between longitudinal and circular muscle) and submucosal plexus
|
|
what are the three main types of chemical signalling in the enteric nervous system?
|
synaptic transmission (neuron to neuron)
endocrine (enteroendocrine cell) paracrine (enterochromaffin cell or enteric mast cell) |
|
what is released by enteroendocrine cells to produce the peristaltic reflex?
|
5-HT
|
|
what do excitatory interneurons associated with the peristaltic reflex release?
|
ACh
SP |
|
what is released by inhibitory interneurons associated with the peristaltic reflex?
|
VIP
|
|
t/f... during the peristaltic reflex, there is relaxation distally and contraction proximally
|
true
|
|
what is the paraympathetic supply to the GIT from the oesophagus to the ascending colon?
|
vagus
|
|
what is the parasympathetic supply to the distal colon and rectum?
|
pelvic splanchnic nerves (sacral spinal cord)
|
|
what neurotransmitter is involved in the parasympathetic supply to the GIT?
|
ACh
|
|
what is the most important neurotransmitter in sympathetic control of the GIT?
|
noradrenaline
|
|
what is the sympathetic supply to the GIT?
|
thoracolumbar spinal cord (sympathetic ganglia/intramural plexus)
|
|
what are the symptoms of oesophagus dysmotility?
|
heartburn
dysphagia regurgitation chest pain |
|
what are the symptoms of stomach dysmotility?
|
dyspepsia
nausea vomiting anorexia early satiety |
|
what are the symptoms of small intestine dysmotility?
|
abdominal pain
bloating abdominal distension |
|
what are the symptoms of colon dysmotility?
|
abdominal pain
diarrhoea constipation |
|
what are the symptoms of anorectum dysmotility?
|
urgency
incomplete evacuation incontinence straining |
|
is typhoid associated with constipation or diarrhoea?
|
constipation
|
|
what are the clinical features of typhoid?
|
persistent continuous fever
travel weight loss constipation splenomegaly |
|
where are the Peyer's patches?
|
ileum
|
|
what is the incubation period of typhoid?
|
7-15 days
|
|
what is the relapse rate of typhoid?
|
10%
|
|
how is typhoid diagnosed?
|
blood culture
|
|
when will the urine be positive for typhoid?
|
after the second week of infection
|
|
what are the major complications of typhoid?
|
perforation
haemorrhage |
|
what is the antibiotic treatment of first choice for typhoid?
|
ceftriaxone, cefotaxime
|
|
which macrolide has useful activity against typhoid?
|
azithromycin
|
|
which organisms cause dysentery?
|
shigella
campylobacter jejuni E coli Entamoeba histolytica Clostridium difficile |
|
which organism causes psuedomembranous colitis?
|
clostridium difficile
|
|
what is the incubation period of dysentery?
|
1-3 days
|
|
what are the symptoms of dysentery?
|
fever
colicky pain in lower abdomen rectal urgency tenesmus |
|
what it the duration of dysentery?
|
2-20 days
|
|
dysentery due to which organism has the longest duration?
|
shigella
|
|
what is the taxonomy of shigella?
|
gram negative rod
|
|
what is the taxonomy of campylobacter?
|
gram negative spiral bacillus
|
|
how is shigella treated?
|
quinolones
cotrimoxazole |
|
what is the treatment of campylobacter?
|
quinolones
macrolides |
|
what is the pathogenesis of EHEC?
|
bacterial cells attach to, and efface gut epithelial cells
production and absorption of shiga (vero) toxin damage to vascular endothelium, especially glomeruli |
|
what are the clinical features of EHEC?
|
haemorrhagic colitis
intravascular haemolysis renal failure |
|
how is EHEC diagnosed?
|
faecal detection of associated serotypes (e.g. O157, O111)
|
|
which form of colitis occurs following antibiotic treatment?
|
clostridium difficile
|
|
how is C. difficile diagnosed?
|
detection of toxins in stools or culture
|
|
how is C difficile treated?
|
cessation of antibiotics
administration of oral metronidazole (or vancomycin) |
|
which antibiotics never cause colitis due to clostridium difficile?
|
aminoglycosides
|
|
which antibiotics are most commonly associated with clostridium difficile colitis?
|
clindamycin
beta-lactams |
|
what is the most common cause ot diarrhoea in hospital?
|
antibiotics (including C. difficile colitis)
|
|
what are the causes of diarrhoea in hospital?
|
antibiotics
noroviruses hyperosmolar solutions elixirs containing sorbitol or mannitol drugs e.g. colchicine ischaemic colitis |
|
what are the side effects of dopamine receptor antagonists?
|
dystonia
dyskinesia |
|
how does ondansetron work?
|
5-HT3 receptor antagonist
|
|
why are opiates avoided in shigellosis, c.difficile and EHEC?
|
can cause toxic megacolon
|
|
what nerve triggers the fed pattern?
|
vagus
|
|
what mediates tonic inhibition in the gut?
|
sympathetic system
|
|
what is the origin of the external oblique?
|
lower 8 ribs (interdigitating with serratus anterior)
|
|
where does external oblique insert?
|
anterior half of outer lip of iliac crest and ASIS, pubic tubercle, pubic crest, pubic symphysis, pectineal line, linea alba, xiphoid process
|
|
where is the free posterior border of external oblique?
|
from R12 to middle of iliac crest
|
|
where is the free lower border of the external oblique?
|
from ASIS to pubic tubercle as inguinal ligament
|
|
what is the origin of the internal oblique?
|
lumbar fascia, anterior 2/3 iliac crest, lateral 2/3 inguinal ligament
|
|
where does internal oblique insert?
|
12, 11, 10 ribs and costal cartilages
9, 8, 7 costal cartilages xiphoid process, linea alba, pubic crest, pectineal line |
|
what is the free border of the internal oblique?
|
conjoint tendon
|
|
where does transversus abdominis originate?
|
inner surface of costal cartilages to 12 (interdigitating with diaphragm), lumbar fascia, anterior 2/3 iliac crest, lateral 1/3 inguinal ligament
|
|
where does transversus abdominis insert?
|
xiphoid process, linea alba, pubic crest, pectineal line
|
|
what does the free border of the transversus abdominis form?
|
conjoint tendon
|
|
what forms the conjoint tendon?
|
free borders of internal oblique and transversus abdominis
|
|
which muscle arises from the outer surface of the ribs, interdigitating with serratus anterior?
|
external oblique
|
|
which muscle arises from the inner surface of the costal cartilage, interdigitating with the diaphragm?
|
transversus abdominis
|
|
where is the origin of rectus abdominis?
|
pubic crest, anterior ligament of pubic symphysis
|
|
what is the insertion of rectus abdominis?
|
anterior surface of xiphoid process, costal cartilages 5,6, 7
|
|
what is the origin of pyramidalis?
|
pubic crest
|
|
where does pyramidalis insert?
|
linea alba
|
|
where does the posterior rectus sheath end?
|
arcuate line
|
|
what is the blood supply of the rectus abdominis muscle?
|
superior and inferior epigastric arteries
|
|
where is the neurovascular plane of the anterior abdominal wall?
|
between transversus abdominis and internal oblique
|
|
what forms the lateral umbilical ligament?
|
inferior epigastric artery
|
|
what forms the median umbilical ligament?
|
urachus
|
|
what forms the medial umbilical ligament?
|
obliterated umbilical artery
|
|
what is the nerve supply to the muscles of the anterior abdominal wall?
|
muscles supplied segmentally by intercostal nerves 7-11, subcostal nerve, iliohypogastric and ilioinguinal nerves
|
|
what is the nerve supply to pyramidalis?
|
subcostal nerve
|
|
where does a femoral hernia arise relative to the pubic tubercle?
|
below and lateral
|
|
where does an inguinal hernia arise relative to the pubic tubercle?
|
above and medial
|
|
what percentage of all hernias are inguinal?
|
73%
|
|
what percentage of hernias are femoral?
|
17%
|
|
what percentage of hernias are umbilical/paraumbilical?
|
9%
|
|
where is the supracolic compartment?
|
above the transverse colon
|
|
where is the infracolic compartment?
|
below the transverse colon
|
|
what is the blood supply to the greater omentum?
|
gastroepiploic arch
|
|
how many subphrenic spaces are there?
|
6
|
|
what are the subphrenic spaces?
|
right anterior subphrenic space
right posterior subphrenic space superior recess of lesser sac left anterior subphrenic space left posterior subphrenic space hepatorenal pouch |
|
what is the ligamentum teres?
|
remnant of umbilical vein
|
|
what separates the right and left anatomical lobes of the liver?
|
groove for IVC and fundus of gall bladder
|
|
how many segments does the liver have?
|
8
|
|
what sign on x-ray indicates a perforated peptic ulcer?
|
gas under the diaphragm
|
|
describe Calot's triangle
|
right-angled triangle: hypotenuse - gall bladder & cystic duct
lower border of liver common hepatic duct, right hepatic duct and right hepatic artery |
|
what is located at each of the corners of a hepatic lobule?
|
bile duct
portal vein hepatic artery |
|
where does blood flow from the portal vein and hepatic artery?
|
into sinusoids to central vein
|
|
what separates sinusoids in the liver?
|
single layer of hepatocytes (covered by the endothelium of the sinusoids)
|
|
what percentage of cells in the liver are hepatocytes?
|
94%
|
|
what are hepatocytes?
|
epithelial cells with apical membranes opposing each other
|
|
what cells are present in the liver?
|
hepatocytes (94%)
Kupffer cells (2%) endothelial cells (2.5%) ito (stellate) cells (1.4%) pit cells (0.1%) |
|
where are kupffer cells located?
|
sinusoidal lumen
|
|
how do liver endothelial cells differ from other endothelial cells?
|
they have spaces between them (fenestrations)
|
|
what is the name of the thin layer of connective tissue between the hepatocytes and the endothelium?
|
space of disse
|
|
what type of cell is located in the space of disse?
|
stellate cells
|
|
where are pit cells?
|
in the sinusoids
|
|
what is the function of endothelium in the liver?
|
physical barrier
uptake of HDL, LDL hydrolysis of lipoproteins due to lipoprotein lipase activity |
|
what type of cell is responsible for hydrolysis of lipoproteins?
|
endothelial cells
|
|
which cell contains lipoprotein lipase?
|
endothelium
|
|
what enables endothelial cells to take triglycerides out of chylomicrons in blood?
|
lipoprotein lipase
|
|
what is the function of Kupffer cells in the liver?
|
phagocytosis and endocytosis of micro-organisms, cell debris, tumour cells etc.
defence clearing endotoxins production of chemokines and cytokines |
|
why do patients with liver failure have a constant state of inflammation?
|
failure of Kupffer cells to clear endotoxins
|
|
what is the function of stellate cells in the liver?
|
fat storage
storage of vitamin A contractile (regulate blood flow through sinusoids) synthesise connective tissue secrete growth factors |
|
what is the function of pit cells in the liver?
|
natural killer cells
directed against viruses, bacteria and tumour cells |
|
what are the functions of hepatocytes (8)?
|
glucose and carbohydrate metabolism
protein and amino acid metabolism acid base balance lipid metabolism clearing/excretory functions - clearing peptide and other hormones excreting and detoxifying organic molecules (endogenous and exogenous) homeostasis of trace metals bile production |
|
what does hepatocyte cell volume indicate?
|
availability of metabolic substrates from the gut
|
|
what happens to the volume of hepatocytes during starvation?
|
hepatocytes shrink
|
|
what happens to hepatocytes after a meal?
|
hepatocytes swell
|
|
what is stimulated by an increase in hepatocyte cell volume?
|
protein synthesis
glycogen synthesis |
|
what is inhibited by an increase in hepatocyte cell volume?
|
proteolysis
glycogenolysis glycolysis |
|
what percentage of dietary carbohydrate is glucose?
|
70%
|
|
what percentage of dietary carbohydrate are monosaccharides?
|
30%
|
|
what happens to glucose in the hepatocyte?
|
converted to glycogen and stored
converted by glycolysis to acetyl CoA exported into circulation |
|
in a well fed person, what percentage of liver weight is stored glycogen?
|
10%
|
|
what is the non-dietary source of glucose?
|
gluconeogenesis (from metabolism of amino acids)
|
|
what is the source of amino acids for gluconeogenesis?
|
diet
proteolysis in liver proteolysis in muscle (in times of starvation) |
|
what is the effect of insulin on carbohydrate metabolism in the liver?
|
increase in glycogen synthesis
increased glycolysis net effect -> storage of glucose as glycogen or fat |
|
what is the effect of glucagon on carbohydrate metabolism in the liver?
|
glycogen breakdown
gluconeogenesis net effect -> release of glucose from stores in liver |
|
what is the effect of catecholamines on carbohydrate metabolism in the liver?
|
glycogen breakdown
|
|
t/f... GLUT2 uses an active mechanism
|
false, it is a diffusion mechanism
|
|
what stimulates conversion of glucose into glycogen in the hepatocyte?
|
plasma glucose
amino acids insulin parasympathetic NS cell swelling |
|
what inhibits conversion of glucose into glycogen?
|
starvation
glucagon |
|
what stimulates conversion of glycogen into glucose?
|
glucagon
cAMP catecholamines sympathetic NS cell shrinkage starvation |
|
what inhibits conversion of glycogen into glucose?
|
glucose
insulin |
|
how does glucagon stimulate the breakdown of pyruvate?
|
inhibiting enzymes that regulate glycolysis (6-phosphofructokinase and pyruvate kinase)
stimulating enzymes that regulate gluconeorgenesis (fructose 1,6-diphosphotase, phosphoenolpyruvate carboxykinase) |
|
what is the function of albumin in plasma?
|
maintains oncotic pressure
|
|
what is bound to bilirubin in the plasma?
|
albumin
|
|
which coagulation factors are synthesised by the liver?
|
all except factor VIII
fibrinogen |
|
t/f... anticoagulation factors are synthesised by the liver
|
true
|
|
what are the two ways to get rid of ammonium?
|
conversion to amino acid
conversion to urea |
|
what is produced by the interaction of bicarbonate and ammonium?
|
carbomoyl phosphate
|
|
under normal pH, what happens to ammonium ions?
|
converted to urea and excreted
|
|
during acidosis, what happens to ammonium?
|
excreted by kidneys as glutamine
|
|
what is heme converted to before reduction to bilirubin?
|
biliverdin
|
|
how is bilirubin excreted from the liver?
|
bound to albumin
|
|
how are peptide hormones inactivated by liver?
|
proteolysed by endothelial enzymes
|
|
how are steroid hormones inactivated by the liver?
|
taken up by hepatocytes and secreted into bile
|
|
how is thyroid hormone activated by the liver?
|
T4 converted to T3 by endothelium
|
|
how is vitamin A stored by liver?
|
in fat globules of stellate cells
|
|
how are xenobiotics eliminated by liver?
|
physical removal from blood (Kupffer cells)
biocemical (metabolism by hepatocytes) |
|
what are the two phases of hepatocyte metabolism of xenobiotics?
|
phase I - generation of a more polar product
phase II - conjugation to increase water solubility |
|
what are the sources of cholesterol in the liver?
|
intestinal absorption of chylomicrons (0.1-0.5 g/day)
synthesis in liver (1g/day) |
|
how is lipid excreted from the liver?
|
secreted in bile
bile salts produced from cholesterol secreted in VLDLs |
|
what produces chylomicrons?
|
intestine
|
|
what are the two types of liver failure?
|
acute liver failure (sudden massive hepatocyte destruction)
chronic liver failure |
|
what is the usual cause of chronic liver failure?
|
cirrhosis
|
|
what is the hallmark of cirrhosis?
|
nodularity
|
|
what are the pathological features of cirrhosis?
|
extensive fibrosis
formation of regenerative nodules hepatocyte necrosis collapse of supporting reticulin network connective tissue deposition distortion of vascular bed nodular regeneration of remaining liver parenchyma |
|
what are the two key steps in cirrhosis?
|
hepatocyte/biliary cell injury
activation of hepatic stellate cells |
|
what drives HSC activation?
|
TGF beta
PDGF |
|
what is the effect of TGF beta and PDGF in cirrhosis?
|
fibrosis and ECM deposition
|
|
what is the mechanism of regenerative nodules in cirrhosis?
|
hepatocyte proliferation and apoptosis
|
|
t/f... regenerative nodules contain a central vein
|
false
|
|
what are the two clinical hallmarks of cirrhosis?
|
failure of hepatocytes to function
development of portal hypertension |
|
why does portal hypertension occur with cirrhosis?
|
scar tissue in vascular bed
|
|
what are the causes of chronic liver disease?
|
viral hepatitis (HBV, HCV), alcoholic liver disease, NASH, autoimmune, metabolic, alpha-1 antitrypsin deficiency, toxins, drugs, budd-chiari syndrome, chronic biliary obstruction, cryptogenic
|
|
what is Budd-Chiari syndrome?
|
vascular obliteration of hepatic veins
|
|
what are the major complications of liver failure?
|
ascites and oedema
spontaneous bacterial peritonitis hepatorenal syndrome hepatic encephalopathy portal hypertensive syndrome hepatopulmonary syndrome hepatocellular carcinoma malnutrition bone disease |
|
what lung pathology is associated with ascites?
|
hepatic hydrothorax (pleural effusion associated with cirrhosis and portal hypertension, usually right-sided)
|
|
what side is affected by the pleural effusion associated with ascites?
|
right
|
|
how is cirrhotic ascites differentiated from malignant ascites?
|
serum-ascitic fluid albumin gradient (>11g/L cirrhosis, <11 g/L malignancy)
|
|
t/f... sodium retention occurs before ascites
|
true
|
|
what is the pathogenesis of ascites?
|
portal HTN -> NO production in splanchnic vessels -> splanchnic arterial vasodilatation -> decreased effective blood volume -> activation of RAAS, sympathetic nervous system and ADH -> Na and water retention -> increase in plasma volume -> continous Na and water retention (increase in plasma volume is inadequate to normalise circulatory homeostasis)
|
|
what is the minor pathway in the pathogenesis of ascites?
|
lymph formation exceeds lymph return
|
|
what will be the result of increased pressure and decreased albumin?
|
ascites
|
|
what are the three major contributing factors to ascites?
|
increased pressure
decreased albumin sodium retention |
|
what is the mechanism of renal sodium and water retention in cirrhosis?
|
increased antinatriuretic and antidiuretic factors (NA, RAAS, ADH)
decreased natriuretic factors (ANP, PGs) |
|
what is the one year survival rate of ascites?
|
60%
|
|
how does refractory ascites affect survival?
|
60% survival at 6 months (cf 60% at 1 year with ascites)
|
|
what are the complications of diuretics in cirrhosis?
|
hyponatraemia
hyperkalaemia hepatic encephalopathy renal impairment gynaecomastia muscle cramps |
|
what percentage of hospitalised cirrhosis patients develop spontaneous bacterial peritonitis?
|
10-30%
|
|
what is the mechanism of spontaneous bacterial peritonitis?
|
bacterial translocation from intestinal lumen to systemic circulation
bacteraemia secondary to impaired RES phagocytic activity defective antimicrobial activity of ascitic fluid leads to ascitic infection |
|
how is spontaneous bacterial peritonitis diagnosed?
|
>300 WCC in ascites
culture ascites into BC bottles |
|
what percentage of organisms causing SBP are gram negative?
|
70%
|
|
what percentage of organisms causing SBP are strep?
|
30%
|
|
what is given as a prophylactic for SBP?
|
norfloxacin (quinolone antibiotic)
|
|
what is the 6 month survival of SBP?
|
50%
|
|
what is the hepatorenal syndrome?
|
progressive renal failure associated with advanced cirrhosis and ascites without intrinsic renal disease
|
|
what does a gradual rise in creatinine while urine output falls indicate?
|
hepatorenal syndrome
|
|
which type of hepatorenal syndrome has a rapid onset?
|
type 1
|
|
t/f... severe hyponatraemia indicates a poor prognosis
|
true
|
|
how is dilutional hyponatraemia treated?
|
limit diuretics
fluid restriction no current pharmacological treatment |
|
what percentage of blood supply to the liver is arterial?
|
30%
|
|
t/f... the portal venous system operates under high pressure
|
false
|
|
how many connections are there from the portal to the systemic systems?
|
5
|
|
what percentage of patients with cirrhosis will develop oesophageal varices?
|
35-80%
|
|
what percentage of patients with oesophageal varices bleed?
|
25-40%
|
|
what is the mortality of bleeding from oesophageal varices?
|
20-50%
|
|
at what pressure is there established portal hypertension?
|
10 mm Hg
|
|
what pressure is the threshold for oesophageal variceal haemorrhage?
|
12 mm Hg
|
|
why is splenomegaly a feature of portal hypertension?
|
high pressure in splenic vein
|
|
what are the two main effects of lactulose?
|
reduced ammonia absorption
increased nitrogen excretion |
|
what are the five factors considered in the Child-Turcotte Pugh grading system for cirrhosis?
|
ascites
encephalopathy bilirubin serum albumin INR |
|
which parameters are used in the MELD score?
|
creatinine
bilirubin INR |
|
at which MELD score does a transplant become necessary?
|
20-29
|
|
which hepatitis viruses cause chronic hepatitis?
|
B, C, D
|
|
which hepatitis virus can become part of the host's genome?
|
HBV (it is a DNA virus)
|
|
how are HAV and HEV transmitted?
|
foecal oral (contaminated food or water)
|
|
when may HAV be transmitted via blood transfusion?
|
if blood donor is viraemic at time of donation
|
|
which liver enzymes will be elevated in acute Hep A?
|
AST, ALT
|
|
what is the laboratory criteria for diagnosis of acute hepatitis A?
|
IgM antibody to hepatitis A virus (anti-HAV IgM) positive
|
|
what does anti-HAV IgG indicate?
|
patient has been infected or vaccinated in the past
|
|
t/f... jaundice is very unusual in children infected with hepatitis A
|
true
|
|
what fraction of the world's population has been infected with Hepatitis E?
|
1/3
|
|
what is the case fatality rate for hepatitis E overall and for pregnant women?
|
1-3%
15-25% for pregnant women |
|
t/f... immunoglobulin is effective against hep E
|
false
|
|
what type of virus is HCV?
|
RNA flavivirus
|
|
how does HCV replicate?
|
RNA dependent RNA polymerase
|
|
which genotypes of HCV are seen in Australia?
|
1b and 3a
|
|
what percentage of people infected with HCV will clear the virus?
|
15-30%
|
|
which populations in Australia have HCV?
|
migrants
IVDU |
|
how is HCV transmitted?
|
parenteral (major form of transmission)
mother-to-child (2% risk) sexual (1-2% risk) |
|
what percentage chance is there of transmitting HCV from a person with HCV following a needlestick injury?
|
3%
|
|
what does anti-HCV antibody indicate?
|
either have infection or have been exposed in the past
|
|
how is HCV viraemia confirmed following a positive anti-HCV antibody?
|
PCR
|
|
how many genotypes of HCV exist?
|
6
|
|
what is the average incubation period for HCV?
|
6-7 weeks
|
|
what percentage of HCV-infected persons develop chronic infection?
|
60-85%
|
|
what are the causes of flares of ALT elevation in HCV positive patients?
|
natural history of infection
viral superinfection drug hepatotoxicity herbal hepatotoxicity fatty liver alcohol |
|
t/f... a liver biopsy is required before treatment of HCV can be commenced
|
false
|
|
what percentage of HCV infected patients will develop extrahepatic manifestations?
|
1-2%
|
|
what is the success rate for treatment of genotype 1 or 4 of HCV?
|
50% with 12 months therapy
|
|
what is the success rate of treatment fro genotype 2/3 of HCV?
|
80%
|
|
when is treatment of chronic HCV contraindicated?
|
decompensated liver disease
|
|
how does most transmission of HBV occur in Asia and Africa?
|
mother to child
|
|
how does most transmission of HBV occur?
|
perinatal/vertical
|
|
how does most transmission of HBV in adults in areas of low endemicity occur?
|
parenteral or sexual
|
|
what is the fatality rate of hepatitis B?
|
0.5-1%
|
|
what is the hallmark of acute hep B?
|
IgM anti-HBc
|
|
what are the major sequelae of HBV infection?
|
cirrhosis
liver failure HCC |
|
what serological pattern is seen in replicative HBV?
|
positive HBsAg
positive HBeAg positive IgG anti-HBc negative anti-HBs negative anti-HBe positive HBV DNA |
|
what serological pattern is seen in non replicative HBV?
|
positive HBsAg
neg HBeAg positive anti-HBc IgG neg anti-HBs positive antiHBe neg HBV DNA |
|
what serological pattern is seen in cleared HBV infection?
|
pos anti-HBc IgG
pos anti-HBs pos anti-HBe |
|
what serological pattern is seen with HBV vaccination?
|
pos anti-HBs
|
|
why does HDV need HBV to replicate?
|
HDV requires HBV for synthesis of envelope protein composed of HBsAg which is used to encapsulate the HDV genome
|
|
what are the two clinical situations in which patients get HDV?
|
coninfection with HBV
superinfection on top of HBV |
|
how is HDV transmitted?
|
percutaneous (IVDU)
transmucosal (sexual) |
|
for which hepatitis virus is there no IgM to determine acute infection?
|
HCV
|
|
which two responses to foreign compounds comprise hepatic adaptation?
|
hypertrophy of sER
induction and release of enzymes (GGT, alkaline phosphatase) |
|
which drugs are common enzyme inducers in the liver?
|
alcohol
phenytoin phenobarbitol |
|
what are the clinical features of severe drug induced liver disease?
|
jaundice
PT >50% hepatic encephalopathy fulminant rapid development of HE or severe coagulation abnormalities |
|
what dose of paracetamol is required for hepatotoxicity?
|
>12g
|
|
what is the toxic metabolite of paracetamol?
|
NAPQI
|
|
which enzymes are involved in the metabolism of paracetamol to NAPQI?
|
CYP2E1, CYP3A4
|
|
why do chronic alcoholics require less paracetamol for hepatotoxicity to occur?
|
CYP2E1 is upregulated (it has already been induced by alcohol intake)
|
|
if alcohol and paracetamol are taken at the same time, what happens to paracetamol toxicity?
|
toxicity is reduced (alcohol competes for CYP2E1)
|
|
why does fasting increase paracetamol toxicity?
|
fasting reduces GSH (enzyme required to detoxify NAPQI)
|
|
what is the commonest cause for liver transplant due to acute liver failure?
|
paracetamol toxicity
|
|
what does N-acetylcysteine (Parvolex) do?
|
replenishes GSH
|
|
what type of hepatotoxicity may occur with methotrexate, arsenic and hypervitaminosis A?
|
hepatic fibrosis
|
|
which component of the OCP is most likely responsible for pill-induced cholestasis?
|
oestrogen
|
|
what separates the caudate lobe from the quadrate lobe of the liver?
|
porta hepatis
|
|
what divides the left and right anatomical lobes of the liver?
|
falciform ligament and fissures for ligamentum venosum and teres
|
|
what divides the functional lobes of the liver?
|
a line passing through the fossae for the gall bladder and IVC
|
|
what is the ligamentum teres a remnant of?
|
umbilical vein
|
|
what is the ligamentum venosum a remnant of?
|
ductus venosus
|
|
what covers the surface of hepatocytes adjacent to the space of Disse?
|
microvilli
|
|
where is bile produced and secreted?
|
bile is produced by hepatocytes and secreted into bile canaliculi
|
|
where does the lesser omentum attach to the liver?
|
at the fissure for ligamentum teres and the porta hepatis
|
|
how much blood does the liver receive per minute?
|
1.5L
|
|
which structures enter the liver at the porta hepatis?
|
L and R branches of portal vein
L and R branches of proper hepatic artery efferent autonomic nerves |
|
which structures exit the liver at the porta hepatis?
|
L and R hepatic ducts
lymphatic vessels visceral afferents |
|
what is the venous drainage of the liver?
|
2-3 large hepatic veins -> IVC
|
|
what is the lymphatic drainage of the liver?
|
through porta hepatis to the thoracic duct
|
|
how big is a liver lobule?
|
1 mm diameter
|
|
what is contained in portal triads which lie between liver lobules?
|
branches of hepatic artery and portal vein, tributaries of hepatic duct and lymph vessels
|
|
where is oxygen tension greatest and lowest in the liver lobule?
|
greatest near portal triad
lowest near central vein |
|
t/f... toxins entering liver will tend to damage cells close to central vein
|
false, cells near portal triad are damaged first
|
|
which cells are affected first by slowing of the hepatic circulation?
|
cells near the central vein
|
|
when is the space of Disse one of the sites of haemopoiesis?
|
foetus
anaemic adult |
|
where does the proper hepatic artery arise from?
|
coeliac trunk
|
|
where do the hepatic veins drain?
|
IVC
|
|
what happens to excess glucose once hexokinase capacity is exceeded?
|
liver glucokinase phosphorylates the glucose to produce G 6-P which is converted into glycogen
|
|
why does the process of glycolysis rarely occur in the liver?
|
high concentration of ATP inhibits phosphofructokinase
|
|
what controls the conversion of liver glycogen to glucose?
|
glucagon
|
|
once sufficient glycogen is synthesised following carbohydrate intake, what happens to excess carbohydrate?
|
it is channeled through the glycolytic pathway in the liver and converted into acetyl CoA which is converted into long chain fatty acids
|
|
what happens to ingested LCFAs?
|
converted into triglycerides which are transported to adipose tissue as VLDLs for storage
|
|
what happens to acetyl coA derived from adipocytes?
|
may be completely oxidised by citric acid cycle to produce ATP or may be converted into 3-hydroxy-3-methylglutaryl CoA
|
|
what happens to amino acids in the liver?
|
deaminated and converted to glucose or acetyl CoA
|
|
what is lactate?
|
end-product of glucose metabolism by erythrocytes and active white muscle
|
|
what happens to lactate in the liver?
|
30% is processed by oxidation
70% converted to glucose |
|
how is autoimmune hepatitis recognised on liver biopsy?
|
inflammatory portal tract infiltrate enriched in plasma cells
|
|
what type of inflammatory infiltrate is associated with alcoholic liver disease?
|
neutrophil
|
|
where does HBV replication occur?
|
mainly in the hepatocyte
also in salivary glands, pancreas, testis |
|
what does the presence of HBeAg in serum indicate?
|
active virus synthesis is occurring in the liver
|
|
what does lamividine target?
|
the viral RT enzyme
|
|
what ALT and AST values occur in alcoholic hepatitis?
|
AST>ALT and values are rarely 10xN elevated
|
|
where are alkaline phosphatase and GGT present?
|
hepatocyte plasma membrane
|
|
what is a common cause of raised plasma levels of alkaline phosphatase and GGT?
|
cholestasis
|
|
what type of hyperbilirubinaemia is associated with liver disease?
|
mixed conjugated and unconjugated
|
|
what type of hyperbilirubinaemia is associated with cholestasis?
|
conjugated
|
|
what is commonest cause of mild unconjugated hyperbilirubinaemia?
|
Gilbert's syndrome
|
|
what is the most useful test of impaired liver function in acute liver failure?
|
PT
|
|
t/f... a prolonged PT in acute liver failure will correct with vitamin K
|
false
|
|
t/f... a prolonged PT associated with cholestasis will correct with vitamin K
|
true
|
|
in which situations may alpha-fetoprotein be raised?
|
HCC
active cirrhosis |
|
which genetic disorders may cause cirrhosis?
|
haemachromatosis
Wilson's disease alpha-1 antitrypsin deficiency |
|
which autoimmune diseases cause chronic cholestasis?
|
primary biliary cirrhosis
primary sclerosing cholangitis |
|
which drugs may damage the biliary system?
|
anti-psychotic drugs
antibiotics |
|
what is the main source of extracellular matrix production in the liver?
|
stellate cell
|
|
which liver enzyme is elevated in chronic hepatitis?
|
ALT
|
|
what causes acute liver failure?
|
hepatitis viruses (particularly HBV)
toxins (paracetamol overdose, mushroom poisoning) |
|
what percentage of cases of acute liver failure are idiopathic?
|
up to 30%
|
|
how is autoimmune hepatitis recognised?
|
presence of various autoantibodies in serum (ANA, SMA)
significant increase in total serum IgG levels |
|
how is genetic haemachromatosis detected?
|
increased serum iron, percentage transferrin saturate, ferritin
|
|
who gets PBC?
|
middle aged women
|
|
which disease is associated with a characteristic anti-mitochondrial antibody (AMA) directed at the pyruvate dehydrogenase complex on the inner mitochondrial membrane?
|
PBC
|
|
in what percentage of cases is PSC associated with inflammatory bowel disease?
|
70%
|
|
what does PSC involve?
|
destruction and damage to the biliary system at all levels
|
|
what is characteristically seen on imaging in PSC?
|
strictures and dilatation throughout the liver
|
|
what characterises liver failure in cirrhosis?
|
effects of portal hypertension: development of portosystemic shunts, hepatic encephalopathy, spontaneous bacterial peritonitis, ascites
|
|
which patients are particularly at risk of HCC development?
|
patients with HBV, HCC, haemachromatosis
|
|
what is the treatment for HCV?
|
interferon-alpha plus ribavirin
|
|
what treatment for autoimmune hepatitis improves 5 year mortality from 40% to below 10%?
|
corticosteroids given with azathioprine
|
|
how is ascites managed?
|
salt restriction
aldosterone antagonist diuretic (1st choice) loop diuretic (2nd choice) paracentesis |
|
how is encephalopathy treated?
|
lactulose
|
|
what are the survival rates for liver transplantation in adults and children?
|
adults - 80%
children - 90% |
|
which has a wider lumen, jejunum or ileum?
|
jejunum
|
|
which has a thicker wall, jejunum or ileum?
|
jejunum
|
|
which of the jejunum and ileum has very long vasa recti with few arcades?
|
jejunum
|
|
which of the jejunum and ileum has shorter vasa recti with many arcades?
|
ileum
|
|
where in the small bowel is there more fat in the mesentery?
|
distally, ie ileum
|
|
what is a volvulus?
|
bowel twisted on its mesentery
|
|
what is the widest part of the large bowel?
|
caecum
|
|
what is indicated by a sawtooth pattern on barium enema?
|
diverticular disease
|
|
what is the white line of Hilton?
|
groove between internal and external sphincter
|
|
what fills the ischiorectal fossa?
|
loose fat
|
|
where on a clock face do haemorrhoids occur?
|
3, 7 and 11 o'clock
|
|
by how much does does alcohol dependence increase all-cause mortality?
|
2-5 times
|
|
what are the three phases of alcoholic liver disease?
|
steatosis
alcoholic hepatitis/steatohepatitis fibrosis/cirrhosis |
|
what are the cells around the portal tracts called?
|
acinar zone 1
|
|
what are the cells surrounding the central vein called?
|
acinar zone 3
|
|
where does acinar zone 3 steatosis occur?
|
around central veins
|
|
t/f... ethanol toxicity moves from acinar zone 1 to 2 to 3
|
true
|
|
what induces MEOS?
|
chronic ethanol consumption
|
|
t/f... alcohol dehydrogenase is inducible
|
false, it is constitutively present
|
|
which ALDH polymorphism confers reduced capacity to metabolise acetaldehyde?
|
ALDH2*2
|
|
which cytokines are instrumental in enhancing cellular injury in alcoholic liver disease?
|
TNF
TGF-beta |
|
where is the CYP2E1 system active?
|
endoplasmic reticulum
|
|
where does ADH act in the hepatocyte?
|
cytosol
|
|
where does catalase act in the hepatocyte?
|
peroxisomes
|
|
which pathways producing acetaldehyde produce other toxic and metabolic distrubances causing cellular injury in ALD?
|
MEOS
ADH |
|
what decreases the first pass metabolism of alcohol by gastric ADH?
|
fasting (accelerated gastric emptying)
gastrectomy H2 receptor antagonists |
|
why does the CYP2E1 system play a role in ALD?
|
generates a high rate of lipid peroxidation and the formation of ROS
|
|
what is the major intracellular hepatic antioxidant?
|
reduced glutathione (GSH)
|
|
how does chronic alcohol exposure affect mitochondrial GSH?
|
reduces mitochondrial GSH
|
|
what is the role of protein adducts (of acetaldehyde) in ALD?
|
adducts act as neoantigens to incite humoral and cytotoxic immune responses
|
|
how does ethanol generate oxidative stress?
|
peroxidation of lipid membranes
|
|
how does oxidative stress cause cellular injury?
|
formation of adducts
generation of cytokines (TNF, TGF-beta) and stimulation of Kupffer cells peroxidation of cellular membranes oxidation of DNA |
|
what is the major site of early lesions and fibrosis in ALD?
|
acinar zone 3 (centrilobular zone)
|
|
where are CYP2E1 and GSH located in the liver lobule?
|
acinar zone 3
|
|
what is the role of endotoxin in alcoholic liver disease?
|
may enter portal and systemic circulation, generating TNF-alpha leading to oxidative stress
|
|
where does fibrosis start in alcohol consumers?
|
acinar zone 3
|
|
what is the major source of collagen in liver fibrosis?
|
hepatic stellate cells
|
|
what causes the impairment of hepatic regeneration in ALD?
|
altered transmission of growth signals
|
|
what is the effect of nutritional deficiencies on hepatic regeneration?
|
impairment of regeneration
|
|
what is the major factor in carcinogenesis in alcoholics?
|
induction of CYP2E1
|
|
t/f... the prognosis of alcoholic hepatitis is worse for men than for women
|
false, prognosis is worse for women
|
|
t/f... steatosis is a characteristic histological feature of alcoholic liver disease
|
true
|
|
t/f... hepatic granulomas are a characteristic histological feature of alcoholic liver disease
|
false
|
|
t/f... fibrosis in acinar zone 3 is a characteristic histological feature of alcoholic liver disease
|
true
|
|
t/f... ground glass hepatocytes are a characteristic histological feature of alcoholic liver disease
|
false, these are characteristic for HBV
|
|
t/f... pericholangitis is a characteristic finding in alcoholic liver disease
|
false, pericholangitis is typically seen in cirrhosing cholangitis or ulcerative colitis
|
|
t/f... in chronic alcohol consumers ADH is the major hepatic pathway of alcohol metabolism
|
false, this is true for people who are small alcoholic consumers
|
|
t/f... in women an average daily consumption of 60g is regarded as safe
|
false
|
|
t/f... patients with alcoholic cirrhosis are at increased risk of HCC
|
true
|
|
t/f... acetaldehyde dehyrogenase is inducible by chronic alcohol consumption
|
false
|
|
t/f... GSH is the most important antioxidant mechanism within hepatocytes
|
true
|
|
t/f... in the context of chronic alcohol consumption, increased lipopolysaccharide levels cause protein adducts
|
false, acetaldehyde and 2E1 cause the adducts
|
|
t/f... increased levels of cytochrome P450 2E1 promotes lipid peroxidation within hepatocytes
|
true
|
|
what causes pruritis?
|
bile salts deposited under the skin
|
|
where does bile drain into the deodenum?
|
ampulla of vater
|
|
what is bilirubin?
|
breakdown product of haem
|
|
what is the main source of bilirubin?
|
haemoglobin from RBC
|
|
what are the sources of bilirubin?
|
main source is Hb
other sources - catalase, cytochromes |
|
t/f... bilirubin is bound irreversibly to albumin during plasma transport
|
false, it is bound reversibly
|
|
what happens to bilirubin before it is excreted into bile?
|
conjugated with glucuronide
|
|
t/f... unconjugated bilirubin cannot be secreted into canaliculi
|
true
|
|
where does bilirubin conjugation occur?
|
hepatocytes
|
|
t/f... unconjugated bilirubin can be excreted in urine
|
false
|
|
what do bile salts do to cholesterol?
|
keep cholesterol in a soluble state
|
|
what is caused by insufficient excretion of bile salts?
|
ineffective fat digestion and absorption
malabsorption of fat soluble vitamins (ADEK) |
|
which causes of cholestasis cause the most marked bile salt excess?
|
post-hepatic causes
|
|
what are the symptoms of cholestasis?
|
jaundice
pruritis dark urine pale stool |
|
t/f... bilirubin in urine is abnormal
|
true
|
|
what is the hepatitic pattern of LFT abnormalities?
|
elevated ALT, AST
|
|
what is the cholestatic pattern of LFTs?
|
elevated GGT, alkaline phosphatase and bilirubin
|
|
t/f... colicky pain is suggestive of small bowel pain
|
true
|
|
t/f... ulcerative colitis involves the large bowel only
|
true
|
|
t/f... crohn's disease involves the small bowel only
|
false, it can involve small and large bowel
|
|
which part of the bowel is most commonly involved in crohn's disease?
|
terminal ileum
|
|
what is the most common cause of gastroenteritis in Australia?
|
campylobacter (followed by salmonella)
|
|
t/f... swinging fever is characteristic of intra abdominal sepsis
|
true
|
|
t/f... leukopenia is a good prognostic feature for intra abdominal sepsis
|
false, leukopenia indicates a poor prognosis
|
|
what is peritonitis?
|
inflammation of peritoneal cavity
|
|
what is indicated by a history of colicky central pain that progresses to constant right iliac fossa pain?
|
appendicitis
|
|
what is the most common presentation of cholecystitis?
|
biliary colic
|
|
what is Murphy's sign?
|
pain in right upper quadrant on inspiration (as gallbladder hits examiner's hand)
|
|
what condition is indicated by sudden onset of severe upper abdominal pain accompanied by board like rigidity?
|
ruptured peptic ulcer
|
|
what clinical presentation suggests bowel obstruction and infarction?
|
colicky abdo pain and vomiting
distension, localised tenderness, toxic hernial orifices |
|
what pain pattern occurs with pancreatitis?
|
severe central abdo pain radiating through to back
|
|
where do intra abdominal abscesses occur?
|
subphrenic
pelvic retroperitoneal between loops of bowel |
|
what moves to wall off a noxious process in abdominal cavity?
|
omentum
|
|
what contributes to the walling off of intra abdominal abscesses?
|
omentum
adjacent bowel and mesentery fibrinous exudate |
|
what is the first response to noxious stimuli in the abdomen?
|
outpouring of peritoneal fluid
|
|
how does peritoneal fluid enter the systemic circulation?
|
via lymphatics (thoracic duct -> subclavian vein)
|
|
what is the result of entry of toxins into the systemic circulation?
|
septicaemia and shock
|
|
t/f... the most common type of peritonitis is primary (blood-borne) peritonitis
|
false, this is a very rare form of peritonitis
|
|
which bacteria are most commonly the cause of primary peritonitis?
|
pneumococcus
streptococcus E coli |
|
t/f... secondary peritonitis is usually caused by multiple gut organisms
|
true
|
|
what has the most impact on outcome of peritonitis?
|
promptness and efficacy of treatment
|
|
how much bile is produced by the liver each day?
|
900mL
|
|
what are the sources of bile?
|
hepatocytes
bile ducts |
|
t/f... bile ducts are similar to pancreatic ducts
|
true
|
|
what do bile ducts produce?
|
isotonic NaHCO3
|
|
what do hepatocytes produce?
|
a fluid rich in organic molecules and relatively poor in bicarbonate
|
|
what is extrahepatic bile?
|
modified intrahepatic bile
|
|
what makes up intrahepatic bile?
|
bile from hepatocytes and intrahepatic bile ducts
|
|
how much bile is stored by gallbladder per day?
|
500mL
|
|
what are the functions of the gallbladder?
|
storage of bile
concentration of bile (up to 10 fold) |
|
what is the range for sodium in hepatic bile?
|
141-164
|
|
what is the concentration of Na in gallbladder bile?
|
220
|
|
what is the concentration of K in hepatic bile?
|
2.7-6.7
|
|
what is the concentration of K in gallbladder bile?
|
14
|
|
what is the concentration of Ca in hepatic bile and gallbladder bile?
|
hepatic: 1.2-3.2
gallbladder: 15 |
|
what is the concentration of HCO3 in hepatic and gallbladder bile?
|
hepatic: 12-55
gallbladder: 19 |
|
what is the concentration of Cl in hepatic and gallbladder bile?
|
hepatic: 77-117
gallbladder: 31 |
|
what is the concentration of bile acids in hepatic and gallbladder bile?
|
hepatic: 3-45
gallbladder: 45 |
|
what is the concentration of total fatty acids in hepatic and gallbladder bile?
|
hepatic: 2-7
gallbladder: 24 |
|
what is the concentration of bilirubin in hepatic and gallbladder bile?
|
hepatic: 1-2
gallbladder 3 |
|
what is the concentration of phospholipid in hepatic and gallbladder bile?
|
hepatic: 1.4-8.1
gallbladder: 34 |
|
what is the concentration of cholesterol in hepatic and gallbladder bile?
|
hepatic: 1-3.2
gallbladder: 6.3 |
|
what are the two forms of bile production?
|
bile salt dependent
bile salt independent |
|
what is bile salt dependent bile production?
|
bile produced by transporting bile acids/bile salts from the circulation into the bile
|
|
what is enterohepatic recirculation?
|
bile salts in ileum are transported into portal circulation
|
|
t/f... bile acids are derived from cholesterol
|
true
|
|
what is the role of NTCP?
|
transports sodium and bile salts/acids
|
|
what gives bile its colour?
|
bilirubin
|
|
which syndrome presents as severe neonatal jaundice with high levels of unconjugated bilirubin?
|
Crigler-Najjar syndrome
|
|
which enzyme is missing in Crigler-Najjar syndrome?
|
UGT1A1
|
|
what are the health benefits to infants of breastfeeding (strong evidence)?
|
protects against GI infection, otitis media, lower respiratory tract infection, necrotising enterocolitis
|
|
t/f... there is some evidence that breastfeeding protects against UTIs and SIDS and reduces chronic diseases in childhood and later in life
|
true
|
|
what are the benefits of breastfeeding to mothers?
|
reduced postpartum bleeding
more rapid uterine involution reduced risks pre-menopausal breast cancer probable reduced post-menopausal breast cancer and ovarian cancer |
|
which mothers have lower breastfeeding rates?
|
without tertiary qualifications
aged less than 25 living in the most disadvantaged areas some rural AHSs |
|
how common is mastitis?
|
up to 25% breastfeeding women
|
|
t/f... antibiotics are firstline treatment for mastitis
|
false
|
|
what is the commonest causative organism of mastitis?
|
staph aureus
|
|
how many mothers return to work before 6 and 12 months?
|
25% before 6 months
40% before 12 months |
|
where are the paravertebral gutters?
|
either side of vertebral bodies
|
|
where are the abdominal aorta and IVC closest to anterior abdo wall?
|
just above umbilicus
|
|
at which vertebral level is the umbilicus?
|
L3/4
|
|
what are the layers of the anterior abdo wall in the midline?
|
skin
superficial fascia deep fascia (very thin) linea alba transversalis fascia extraperitoneal fat parietal peritoneum |
|
what are the layers of the anterolateral abdo wall laterally?
|
skin
superficial fascia deep fascia external oblique internal oblique transversus abdominis transversalis fascia extraperitoneal fat parietal peritoneum |
|
where do the layers of the anterolateral abdo wall fuse?
|
at the umbilicus
|
|
what is the deepest part of the superficial fascia?
|
membranous layer
|
|
what forms the self-contained pouch that may fill with urine from a ruptured urethra?
|
membranous layer of superficial fascia
|
|
what provides support to the viscera?
|
resting abdo wall muscle tone
|
|
when do abdominal wall muscles contract?
|
forced expiration
to increase intra-abdo pressure to move trunk to protect viscera against injury |
|
what forms the anterior rectus sheath above the arcuate line?
|
1 1/2 aponeuroses
|
|
what forms the anterior layer the rectus sheath below the arcuate line?
|
3 aponeuroses
|
|
what is related to the rectus abdominis posteriorly below the arcuate line?
|
transversalis fascia
|
|
where do the superior and inferior epigastric arteries anastomose?
|
posterior to rectus abdominis muscles
|
|
where is the neurovascular plane in the anterior abdominal wall?
|
between transversus abdominis and internal oblique
|
|
t/f... L1 does not pierce the rectus sheath
|
true
|
|
where is the deep inguinal ring?
|
mid point of inguinal ligament
|
|
what is contained in the inguinal canal?
|
spermatic cord (male)/round ligament (female)
ilioinguinal nerve |
|
an opening in which layer of the abdo wall forms the deep inguinal ring?
|
transversalis fascia
|
|
what is the superficial inguinal ring?
|
opening in external oblique aponeurosis
|
|
where is the superficial inguinal ring in relation to the pubic tubercle?
|
superior and medial
|
|
what attaches to the lateral 2/3 of inguinal ligament?
|
internal oblique
|
|
what attaches to the lateral 1/2 of inguinal ligament?
|
transversus abdominis
|
|
what forms the floor of the inguinal canal?
|
inguinal ligament
|
|
what forms the roof of the inguinal canal?
|
internal oblique and transversus abdominis
|
|
what forms the anterior wall of the inguinal canal?
|
external and internal oblique
|
|
what forms the posterior wall of the inguinal canal?
|
transversalis fascia and conjoint tendon
|
|
what forms Hesselbach's triangle?
|
rectus abdominis
inferior gastric artery inguinal ligament |
|
where does a femoral hernia pass?
|
through femoral ring into upper medial thigh
|
|
what are the boundaries of the femoral ring?
|
femoral vein
inguinal ligament pectineus muscle and fascia lacunar ligament |
|
what is the foregut?
|
oesophagus to prox duodenum (entry bile duct)
|
|
what is the midgut?
|
distal duodenum to 2/3 transverse colon
|
|
what is the hindgut?
|
distal 1/3 transverse colon to upper 1/2 anal canal
|
|
which organs are associated with the foregut?
|
liver
most of pancreas spleen |
|
which organs are associated with the midgut?
|
remainder of pancreas
|
|
what is the arterial supply and venous drainage of the foregut?
|
coeliac trunk
splenic vein |
|
what is the arterial supply and venous drainage of midgut?
|
superior mesenteric artery and vein
|
|
what is the arterial supply and venous drainage of the hindgut?
|
inferior mesenteric artery and vein
|
|
what is the parasympathetic supply to the foregut, midgut and hindgut?
|
foregut - vagus
midgut - vagus hindgut - S2-4 |
|
what is the sympathetic supply to the foregut, midgut and hindgut?
|
foregut - thoracic splanchnic nerves
midgut - thoracic splanchnic nerves hindgut - lumbar splanchnic nerves |
|
where do the coeliac truck and superior and inferior mesenteric arteries leave the aorta?
|
Tv12
Lv1 Lv3 |
|
which arteries arise from the coeliac trunk?
|
left gastric
splenic common hepatic |
|
which arteries arise from the superior mesenteric artery?
|
inferior pancreaticoduodenal
jejunal and ileal branches ileocolic right colic middle colic |
|
which arteries arise from the inferior mesenteric artery?
|
left colic
sigmoidal superior rectal |
|
where does the portal vein travel in relation to the duodenum?
|
posterior to first part of duodenum
|
|
what are the retroperitoneal parts of the gut tube?
|
duodenum (except first few cm)
ascending colon descending colon |
|
what is the epiploic foramen?
|
opening into lesser sac behind free edge of lesser omentum
|
|
what is the greater omentum fused with posteriorly?
|
transverse colon and its mesocolon
|
|
where do the greater and lesser sac communicate?
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epiploic foramen
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what attaches the jejunum and ileum to the posterior abdominal wall?
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mesentery
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where does the oesophagus commence?
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lower border of cricoid cartilage (Cv6)
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which muscle forms the upper oesophageal sphincter?
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cricopharyngeus (lower part of inferior constrictor)
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where does oesophageal epithelium change from stratified sqamous to columnar?
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Z line
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what are the layers of muscle in the oesophagus?
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outer longitudinal
inner circular |
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what are the constriction points of the oesophagus?
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upper oesophageal sphincter
arch of aorta and left main bronchus oesophageal hiatus (Tv10) |
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what is the venous drainage of the three parts of the oesophagus?
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cervical: thyroid vv->SVC
thoracic: azygos vv->SVC abdominal: portal vein |
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what is the lymphatic drainage of the three parts of the oesophagus?
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cervical: deep cervical nodes
thoracic: mediastinal nodes abdominal: coeliac nodes |
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what is the arterial supply of the three parts of the oesophagus?
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cervical: branches of inferior thyroid artery
thoracic: direct/indirect branches of descending thoracic aorta abdominal: left gastric artery |
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what is the innervation of the oesophagus?
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left and right vagus nn (form plexus then ant and post vagal trunks which pass through oesophageal hiatus)
sympathetic trunk |
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where does pain referral occur from the oesophagus?
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substernal pain +/- epigastric pain
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what are the four parts of the stomach?
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cardia
fundus body pyloric part |
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what are the muscular layers of the stomach?
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deep: oblique
middle: circular superficial: longitudinal |
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what are the folds on the interior of the stomach?
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rugae
|
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what thickens to form the pyloric sphincter?
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circular layer of muscle
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what does the lesser omentum attach to?
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lesser curvature of stomach and first few cm of duodenum to liver
|
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what is contained in the greater omentum?
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blood vessels
lymph vessels variable amount of fat |
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what are the anterior relations of the stomach?
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liver
diaphragm ant abd wall |
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what are the posterior relations of the stomach?
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diaphragm
left suprarenal gland and kidney pancreas splenic artery transverse colon and mesocolon |
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at what vertebral levels is the duodenum?
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Lv1-3
|
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what are the folds on the interior surface of the duodenum?
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circular folds (plicae circulares) in all but first few cm
|
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what is the blood supply to the stomach?
|
branches of coeliac trunk:
lesser curvature - L and R gastric aa greater curvature - L and R gastroepiploic arteries fundus - short gastric arteries |
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what is the blood supply to the duodenum?
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sup and inf pancreaticoduodenal aa (from coeliac a and SMA)
|
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which artery may be eroded by a peptic ulcer on the posterior wall of the stomach?
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splenic artery
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which artery may be eroded by a peptic ulcer on the posterior wall of first part of duodenum?
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gastroduodenal artery
|
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what does the gastroduodenal artery branch into?
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gastroepiloic and superior pancreaticoduodenal arteries
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where is the vena caval hiatus?
|
Tv8
|
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where is the oesophageal hiatus?
|
Tv10
|
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where is the aortic hiatus?
|
Tv12
|
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what makes up the posterior abdominal wall?
|
lumbar vertebrae and intervening discs
crura and arcuate ligaments of diaphragm psoas major quadratus lumborum iliacus aponeurosis of transversus abdominis |
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where does the abdominal aorta start and end?
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aortic hiatus (Tv12 in diaphragm)
Lv4 |
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which paired branches of arteries arise from the abdominal aorta?
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suprarenal
renal gonadal (ovarian, testicular) |
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which branches of the abdominal aorta supply the body wall?
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inferior phrenic
lumbar branches median sacral |
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where does the IVC commence?
|
Lv5 bu union of L and R common iliac veins
|
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what are the major tributaries of the IVC?
|
L and R renal
hepatic veins lumbar veins R gonadal R suprarenal |
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t/f... the valves in the trunk are valveless
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true
|
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how do the SVC and IVC anastomose?
|
via veins on anterior trunk wall, via the ascending lumbar/azygos system, vertebral venous plexus and portal system
|
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where do the unpaired viscera drain to (lymph)?
|
preaortic nodes
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where do the structures below the diaphragm excluding unpaired viscera drain to?
|
para-aortic nodes
|
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where do the pre and para-aortic nodes drain to?
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cysterna chyli->thoracic duct->drains to junction L subclavian and L int jug
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palpation of which node is indicated in a routine examination of the abdomen?
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left supraclavicular node (Virchow's node)
|
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what is Troisier's sign?
|
hard and enlarged Virchow's node
|
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where does lymph return to veins?
|
root of neck
|
|
what are the somatic nerves to the posterior abdominal wall?
|
subcostal nerve (T12 ventral ramus)
branches of lumbar plexus (forms in psoas major from ventral rami of L1-4) |
|
where are the sympathetic trunks?
|
in groove between vertebral bodies and psoas major
|
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where is the right symp trunk relative to IVC?
|
posterior
|
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how do L and R symp trunks unite?
|
anterior to coccyx as ganglion impar
|
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how do thoracic splanchnic nerves pass through the diaphragm?
|
pierce the crura
|
|
what are the retroperitoneal structures?
|
suprarenal glands
kidneys ureters pancreas (except tail) duodenum (except first few cm) ascending and descending colon abdo aorta IVC assoc LN and autonomic nn |
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what is the arterial supply to the suprarenal glands?
|
superior, middle and inferior suprarenal aa
|
|
which cells release adrenaline and noradrenaline into circulation via suprarenal veins?
|
chromaffin cells of adrenal medulla
|
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what is the venous drainage of the suprarenal veins?
|
R suprarenal vein->IVC
L suprarenal vein->left renal v |
|
which features distinguish the colon?
|
taeniae coli
haustrations epiploic appendages |
|
what percentage of appendices are retrocaecal? pelvic?
|
64%
32% |
|
what is a positive psoas sign?
|
pain on passive extension of right hip joint with knee extended (indicates appendicitis)
|
|
what is the obturator sign?
|
pain on internal rotation of flexed right hip (indicates appendicitis)
|