Biol 431 - Unit 3 - Digestive System & Metabolism

Oral or buccal cavity

Site of mechanical & chemical digestion

Bone partition between nasal & oral cavities

Closes off nasopharynx to oropharynx during swallowing

Closes off nasopharynx during swallowing

Immune response against foreign inhaled & ingested substances

--Palatine (2) - both sides of oral fauces

--Lingual (2) - inferior to tongue

--Pharyngeal (1) - just behind internal nares

Tongue

Skeletal muscle accessory organ w/ mucous membrane attached to hyoid bone

Lingual lipase

Accessory organ in sockets of alveolar processes of mandible & maxillae

Alveolar processes of mandible & maxillae

Protrusions of mucous membrane that extend slightly into each socket

Dense fibrous CT

Ligament that anchors teeth to socket walls

Visible portion of tooth (above gums)

Portion of tooth embedded in socket

1 to 3

Dentin

Calcified CT (70% of dry weight is Ca2+ salts)

Gives tooth base shape & rigidity

Tooth enamel

--Protects tooth from wear & tear of chewing
--Protects against acids that can easily dissolve dentin

Bone-like structure that attaches root to periodontal ligament

CT containing:

--Blood vessels

--Nerves

--Lymphatic vessels

Extension of pulp cavity where root of tooth runs through

Opening @ base of root canal containing:

--Blood vessels

--Nerves

--Lymphatic vessels

Junction b/w crown & root (near gum line)

3 molars

2 premolars

1 canine

2 incisors

2 teeth closest to midline

Used for cutting into food

Tooth immediately lateral to incisors on either side (R & L)

Used to tear & shred food

2 teeth lateral & posterior to canine on either side (R & L)

Crush & grind food

2 - 3

3 teeth posterior to premolars

Crush & grind food

--Parotid

--Submandibular

--Sublingual

Produce watery saliva to aid in mechanical digestion & amylase

Amylase

Inferior & anterior to ears

Amylase & mucus

Floor of mouth

Mostly mucus

Beneath the tongue, superior to submandibular glands

Passageway for air & food

Opening connecting oral cavity & oropharynx

Common passageway for air/food

Passageway to propel food toward esophagus

Passageway for air

Collapsible muscular tube connecting pharynx to stomach

Propel food (bolus) towards stomach via peristalsis

--Mixes & holds food

--Converts semi-solid bolus to liquid

Peristalsis

Oblique muscles

Circular band of smooth muscle connecting esophagus to stomach

Keep gastric juices from entering esophagus

Circular band of smooth muscle connecting stomach to duodenum of sm. intestine

Regulate the flow of chyme from stomach to duodenum of sm. intestine

Convex, lateral border

Concave, medial border

Lg., central portion of the stomach

Rounded portion of stomach superior & to L of cardia

Inferior part of stomach connecting to duodenum

Connects body of stomach

Leads to pylorus

Leads to duodenum

Folds in mucosa of stomach (when stomach is empty)

Mucosal & submucosal folds that go around the small intestine

Increase surface area

Projections off of plicae

Duodenum

Site of absorption

Opening of the common bile duct into the duodenum

Primary mechanism for the secretion of bile

Papilla of Vater

The cavity behind the duodenal papilla

Ampulla of Vater

Regulate flow of pancreatic juice & bile into duodenum

Second part of sm. intestine that extends into illium

Third & last segment of sm. intestine

Smooth muscle sphincter that opens from sm. intestine into lg. intestine

Secretes pancreatic juice, bicarbonate, and hormones (i.e., insulin & glucagon)

--Head

--Neck

--Body

--Tail

Expanded portion of pancreas near curve of duodenum

Tapering portion of pancreas near spleen

Majority of the pancreas

Portion of pancreas between the pancreatic neck & body

Drains into ampulla of Vater & joins the common bile duct

Leads to pancreas & empties into duodenum

Principal pancreatic duct

Falciform ligament

Connects the liver to the anterior abdominal wall

Extends from liver to umbilicus

Ligamentum teres

Supply O2 rich blood to liver

Drains O2 poor blood from the liver

Carries O2 poor but nutrient rich blood

Empties into common hepatic duct from R & L sides of liver

Joins cystic duct from gallbladder

Where content of gallbladder ejects into

Drains into ampulla of Vater

Lesser omentum

Store & then secrete bile into sm. intestine (under influence of CCK hormone)

--Eliminates wastes & undigested minerals

--(To a lesser degree) Continues reabsorption of H2O & vitamins

Thin muscle fibers forming circular furrows (pouches) along ascending & transverse colons

Fill & distend via muscle contraction to move contents to next haustra

Ribbons of smooth muscle on the ascending, transverse, descending, and sigmoid colons that produce haustral pouches

Small pouch that is the beginning of the lg. intestine

Receives waste from the sm. intestine

Iliocecal valve

Blind-ended tube that is connected to the cecum

Site of immune function

Moves waste from sm. intestine to rectum

4 segments:

--Ascending colon

--Transverse colon

--Descending colon

--Sigmoid colon

6 ft.

1st segment of lg. intestine that stems from cecum upward on the R side of body

2nd segment of lg. intestine that crosses abdomen from R to L

3rd segment of lg. intestine that extends from the splenic flexure to the beginning of the sigmoid colon

Store food waste that will be emptied into the rectum

Feces storage

Bend in colon at juncture of ascending & transverse segments

Bend in colon at juncture of transverse & descending segments

Stores feces

Vertical folds of mucous membrane at upper half of anal canal

Smooth muscle that guard the anus

Skeletal muscle that guard the anus

Any of several veins draining the walls of the anal canal & rectum

Opening of anal canal to exterior

Serous membrane that lines the walls of the abdominopelvic cavity

Serous membrane that covers some organs in the abdominopelvic cavity & other serosa layer

Retroperitoneal organs:

--Organs posterior to abdominal wall (not in peritoneal cavity)

--Not bound by mesentary

Intraperitoneal organs:

--Organs within peritoneal cavity

Bundles of extensions that anchor parts of the GI tract

Largest peritoneal fold from transverse colon down (AKA - the fatty apron)

Attaches liver to diaphragm & anterior abdominal wall

Cellophane-like anchor that binds jejunum & ilium

Peritoneal folds binding transverse colon

Mesentary of appendix that attaches appendix to inferior part of mesentary of ilium

--Epithelium (towards lumen)

--Lamina propria

--Muscularis mucosa

--Inner band of circular muscle fibers

--Outter band of longitudinal muscle fibers

Phagocytic cells forming the lining of liver sinusoids

Sinusoids of liver

Phagocytic cells that break down RBCs

Pancreas

Exocrine

Secrete pancreatic juices with HCO3- and pancreatic enzymes

--Lipase

--Amylase

--Trypsin

--Chymotrypsin

--Caboxypeptidase

--Elastase

--Nuclease

Pancreatic islet (AKA - islet of Langerhans)

(Pancreatic islet or Islet of Langerhans)

Endocrine

--Alpha cells secrete glucagon

--Beta cells secrete insulin

Interlobular duct

Jejunum

Submucosa

Plica circularis

Increase surface area for absorption

Intestinal gland (AKA - crypt of Lieberkühn)

Goblet cells

Secrete mucous

Mucosa

Simple columnar epithelial tissue

Submucosa

Muscularis

(inner layer of circular fibers;

outter layer of longitudinal fibers)

Haustral churning/peristalsis

Liver

Hepatic artery

Bile duct

Bile

Branch of hepatic portal vein

Oxygen poor, nutrient rich blood

(may have toxins)

Hepatocytes

--Secrete bile

--Metabolize lipids, carbs, & proteins

--Detoxification

Fundic stomach

Mucosa

Parietal cells

--HCl

--Intrinsic factor

Chief cells

--Pepsinogen

--Gastric lipase

Gastric gland

Muscularis

Serosa

Myenteric plexus

Regulating motility by regulating muscularis

Tenia coli

External longitudinal layer of muscularis

Peristalsis

Submucosa

Areolar connective tissue

Intestinal glands (AKA - crypts of Lieberkühn)

Colon

--Crypts of Lieberkühn

--No gastric pits or villi

--Tenia coli

Gastroesophageal junction

Lower esophageal sphincter (AKA - cardiac sphincter)

(Lower esophageal sphincter)

--Allow bollus into stomach

--Prevent reflux of acid from stomach into esophagus

Inner circular layer of muscularis

Smooth muscle tissue

Nonkeratinized stratified squamous epithelial tissue (NKSSET)

Simple columnar epithelial tissue

Mucous glands

Secrete mucous

Submandibular gland

Serous acini

Secrete watery saliva with salivary amylase

Interlobular duct

Mucousal tubule

(Mucousal tubule)

Secrete mucous saliva

Intralobular duct

Mucuous tubule

Secrete mucous saliva

Serous acini

(Serous acini) secrete salivary amylase

Intralobular ducts

Submandibular gland

--Serous acini & mucous tubules

--No skeletal muscle

Secrete a mixture of watery saliva & mucous saliva

Esophagus

Lamina propria

Muscularis mucosa

Submucosa

Nonkeratinized stratified squamous epithelial tissue

Mucosa

Muscularis

Adventitia

Liver

Central vein

Hepatocytes

(Hepatocytes)

--Secrete bile

--Metabolize lipids, carbs, & proteins

--Detoxification

Portal triad

Serosa;

Provides lubrication to reduce friction

Esophagus

Nonkeratinized stratified squamous epithelial tissue

Stomach

Simple columnar epithelial tissue

Gastroesophogeal junction

Duodenum

Villus

Plica circularis

Crypts of Lieberkühn

Duodenal glands

Outer longitudinal layer of muscularis

Adventitia

Pancreas

The act of swallowing

--Voluntary: act of tongue forcing bolus against hard palate & into oropharynx

--Pharyngeal: bolus passes into oropharynx

--Esophageal: bolus enters esophagus & moves towards stomach

Gastroesophageal reflux disease: incompetent lower esophageal sphincter allows stomach acid into esophagus

Allows body to absorb vitamin B12

1 - 1.5 L

1 - 1.5 L

Decrease blood sugar

Increase blood sugar

Starch digesting enzyme

--Peptidase

--Trypsin

--Chymotripsin

Triglyceride digesting enzyme in adults

--Ribonuclease

--Dioxyribonuclease

Constipation

Diarrhea

--Cephalic phase

--Gastric phase

--Intestinal phase

Smell, sight, thought, or taste of food

Secretion of saliva & gastric juices

Food enters stomach

--Gastrin promotes secretion of gastric juice & increases gastric motility while relaxing pyloric sphincter

--Acidic chyme enters duodenum

--Duodenal stretch receptors

--(CCK) Detection of amino acids & lipids

--(Secretin) Decreased pH

--Duodenal stretch receptors stimulate sympathetic N.S. to inhibit gastric motility & inhibit pyloric sphincter

--CCK stimulates pancreatic & gallbladder secretion & contracts pyloric sphincter

--Secretin stimulates pancreatic secretion & inhibits gastric secretion

Extract energy stored in reduced co-enzymes (i.e., NADH & FADH2)

--Glycolysis (cytoplasm)

--Formation of Acetyl-CoA (mitochondrial matrix)

--Krebs (mitochondrial matrix)

--ETC (inner membrane)

Breakdown of lipids

Oxidation of lipids to yield glucose (to then yield ATP)

Process of cleaving off 2-carbon fragements from long fatty acid chains that occurs in mitochondrial matrix

Any of 3 ketoacid compounds produced during the metabolism of fats

Normal part of fat breakdown that causes metabolic acidosis when in excess

State of decreased pH due to excessive ketone body buildup

Ketone body that produces sweet smell to someone's breath (symptom of ketoacidosis)

LDL: when produced excessively the cholesterol carried outnumbers bodily need, so cholesterol is just "dumped" along the way & accumulates in arteries

HDL: removes excess cholesterol "dumped" by LDL & transports it to the liver for elimination from the body

A droplet of fat present in the blood or lymph after absorption from the small intestine

Proteins are broken down into amino acids to produce ATP or synthesize new proteins

Converted into glucose (glucogenesis) or triglycerides (lipogenesis)

Removal of an amino group leaving the carbons of a carboxylic acid to be used to make ATP

Transfer of an amino group (NH2) to pyruvic acid or other acid in Krebs cycle to form amino acid (protein anabolism)

Ammonia is produced in the liver & converted to urea to be excreted in urine

Process that converts biochemical energy into ATP

Adding a phosphate group to a molecule

--ATP production

--Amino acid synthesis

--Glycogen synthesis (liver & muscle cells)

--Triglyceride synthesis (lipogenesis)

Regulates the rate at which glycolysis can occur

Loss of electron from substance (reducing agent)

Gain of electron from substance (oxidizing agent)

--Glycogen synthesis

--Amino acid synthesis

--ATP production

--Triglyceride synthesis

Digestion

--Lingual

--Gastric

--Pancreatic

--Parietal cells (intrinsic factor)

--Chief cells (pepsinogen & gastric lipase)

--Mucous cells (mucous)

--Mucous neck cells (mucous)

--G cells (gastrin)

Lumen extending from oral cavity to anus

--Oral cavity

--Laryngopharynx

--Esophagus

--Stomach

--Duodenum

--Jejunum

--Ilium

--Ascending colon

--Transverse colon

--Descending colon

--Sigmoid colon

--Rectum

--Anus

--Tongue

--Teeth

--Salivary glands

--Gallbladder

--Pancreas

--Liver

--Ingestion

--Secretion

--Mixing & propulsion

--Digestion

--Absorption

--Defecation

7 L

Movement of food/waste through GI tract

--Propulsion

--Segmentation

Movement of material through GI tract via peristalsis

Localized mixing contractions in portions of the sm. intestine distended by chyme

Migrating motility complex, a type of peristalsis in sm. intestine that propels chyme

--Mechanical digestion

--Chemical digestion

Chewing food to increase surface area & mix with enzymes

Breakdown of food into usable resources by the body

--Salivary amylase

--Lingual lipase

--H2O

--Mucous

--Lysozymes

--Ions

The opening in the diaphragm through which the esophagus passes

--Mixes saliva, food, & gastric juice (chyme)

--Reservoir for food

--Secretion (gastric juice, gastric lipase, & intrinsic factor)

--Kills bacteria

--Denatures proteins

Begins digestion of proteins

Aids digestion of triglycerides

Extract energy stored in reduced co-enzymes formed during previous stages of cellular respiration

Movement of ions across a selectively permeable membrane down an electrochemical gradient

1. Energy from NADH-H+ passes along ETC & used to pump H+ ions into space between inner & outer membranes

2. High concentration of H+ accumulates in this space

3. ATP synthesis occurs as H+ flows back into matrix thru a H+ channel that includes ATP synthase

1 L

Emulsifies fats for watery environment of sm. intestine digestive juices

Hepatic acinus

--Prehepatic jaundice: excess production of bilirubin

--Hepatic jaundice: due to congenital liver disease, cirrhosis of liver, or hepatitis

--Extrahepatic jaundice: due to blockage of bile drainage by gallstones or cancer to bowels or pancreas

--Neonatal jaundice: mild jaundice in newborns due to immature functioning of liver

--Mechanical digestion (segmentation)

--Chemical digestion (brush border enzymes)

--Absorption (90%)

1 - 2 L

--α-dextrinase

--Maltase

--Sucrase

--Lactase

--Peptidase

--Nucleosidases

--Phosphatases

--Pancreatic amylase

--Pancreatic lipase

--Trypsin

--Chymotripsin

--Peptidase

--Ribonuclease

--Deoxyribonuclease

Absorbtive cells of sm. intestine fail to make enough lactase

Undigested lactose in chyme causes fluid retention in feces & bacterial fermentation of undigested lactose

After consumption of milk & dairy products

--Diarrhea

--Gas/bloating

--Abdominal cramps

Calcitrol

--Gastroilial reflex pushes chyme into cecum

--Gastrocolic reflex pushes contents of colon into rectum

--Defecation reflex triggered by stretch receptors in rectum

--Food in stomach triggers mass peristalsis

--Chyme moves through intestines to rectum

--Rectal pressoreceptors respond to distension

--ANS releases internal anal sphincter & gives conscious awareness of distension

Bilirubin from catabolized RBCs

Reflex inhibiting stomach emptying contents when duodenum is obstructed, overfilled, or irritated

Net sum of all body reactions

Breaking down lg. molecules into sm. molecules

Building up sm. molecules into lg. molecules

Intermediate coenzymes (& B vitamins) that can accept transfer of e- until ADP can be transformed into ATP

Intermediate coenzymes that have accepted transfer of e- & are temporarily storing harvested bond energy until ADP can transforminto ATP

--Chylomicron

--VLDL

--LDL

--HDL

Producing ATP by oxidizing glucose

Maintaining homeostasis of blood glucose levels for neurons & RBCs

Synthesis of glucose from non-carbohydrates

Biochemical way to use & store energy ("energy currency" of the body)