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131 Cards in this Set
- Front
- Back
What are the 4 organs of the urinary system? |
urethra bladder ureters kidneys |
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Where are the kidneys located? |
in the superior lumbar region from T12-L3 |
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true or false: the right kidney is slightly lower than the left one |
true; this is due to the crowding of the liver |
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at what site do structures enter and exit the kidneys? name 3 of these structures: |
the renal hilum; ureters, renal blood vessels, and nerves |
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what lies on top of each kidney? is this a part of the kidney? |
an adrenal gland; no, it is a completely separate organ |
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true or false: the adrenal gland is a part of the urinary system |
false; the adrenal gland is part of the endocrine system |
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what is and what is the f(x) of the outermost external kidney layer, the renal fascia? |
it's a dense connective tissue that anchors the kidney and adrenal gland to surrounding tissues |
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what is the f(x) of the middle external kidney layer, the perirenal fat capsule? |
to surround and cushion each kidney and to keep them in place |
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def ptosis: what does it mean in regards to the kidneys? |
"a fall"; a condition where the kidneys drop to a lower position which can create problems if the ureters become kinked |
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def hydronephrosis: |
the swelling of the kidney due to build-up of urine (due to a blockage or drainage issue) |
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what are the 3 regions in the kidney? |
the renal cortex: the outer region the renal medulla: the middle area the renal pelvis: the inner area (next to hilum) |
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what is the structure and f(x) of calyces? (singular: calyx) |
2 or 3 minor calyces converge to form a major calyx; they collect urine from the kidney which gets drained into the renal pelvis |
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where is urine stored? |
the bladder |
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true or false: the kidneys continuously cleanse the blood and adjust it's composition |
true; approx 1/4 of the total blood supply passes through the kidneys each minute. |
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What is the arterial supply of each kidney? What are it's 4 segments? |
renal artery; renal--> 2 segmental arteries--> (several branches of) interlobar arteries--> arcuate arteries--> cortical radiate arteries |
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what is the pathway of venous blood leaving the kidney? (5 segments) |
cortical radiate veins--> arcuate veins--> interlobar veins--> renal veins--> inferior vena cava |
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what is the f(x)l unit of the kidney; how many does it contain? |
the nephron; over a million |
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what are the 2 main structures of the nephron? |
the renal corpuscle and the renal tubule |
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What is the f(x) of the renal corpuscle? What structures help it to do this? |
filter blood; A knot of capillaries called the glomerulus, which is surrounded by a capsule called Bowman's capsule (or the renal capsule) |
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How does blood get filtered in the renal corpuscle? |
the high-pressure blood enters the glomerulus and causes the blood plasma to push through the capillaries, into the capsule |
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def podocytes:
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highly modified cells that form Bowman's capsule; they have foot processes that make filtration slits which help collect filtrate from the glomerulus |
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true or false: red blood cells get filtered out |
false; they are too large to pass through the filtration membrane (if they did, it would indicate a problem) |
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what happens to filtrate once it leaves the capsule? |
it flows along the renal tubule |
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in what order does filtrate leave the capsule? |
capsule--> proximal convoluted tubule (PCT)--> the nephron loop (Loop of Henle)--> the distal convoluted tubule (DCT)--> collecting ducts |
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Where are the majority of microvilli located? |
PCT (proximal convoluted tubule) |
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Where are the majority of nephrons located? what are they called? |
within the cortex; cortical nephrons |
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what are juxtamedullary nephrons? |
nephrons situated close to the cortex-medulla j(x); (their nephron loops dip deep into the medulla) |
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where do the collecting ducts drain into? |
the calyces and renal pelvis |
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true or false: 99% of filtrate is returned to blood |
true; it's reclaimed in the tubule and returned in the peritubular capillary beds |
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true or false: the glomerulus is both fed and drained by arterioles |
true; these are high-resistance vessels which can handle the high-pressure forces (and also carry oxygenated blood) |
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what give the renal pyramids a striped appearance? |
the collecting ducts because they run through the renal medulla |
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what are the peritubular capillaries? what are they responsible for? |
the second capillary bed, made up of low pressure, porous vessels; responsible for absorption |
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where do the peritubular capillaries arise from? |
arise from the efferent arteriole that drains the glomerulus and cling closely to the renal tubule |
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if blood pressure were too low, what would happen to filtration? |
filtrate formation would stop because glomerular pressure would be inadequate |
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def oliguria |
a urinary output of 100-400mL/day (abnormally low) |
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def anuria: |
urine output less than 100mL/day |
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what are the components of filtrate? |
water and solutes smaller than proteins *NOT blood cells or proteins |
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what substances are usually reabsorbed into the blood? |
water glucose amino acids ions |
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how do substances cross the membrane to reenter the peritubular capillaries? |
passively: water by osmosis active transport: membrane carriers |
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list 3 nitrogenous waste products: |
urea uric acid creatinine |
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what is the f(x) of tubular secretion? how does it accomplish this? |
to control blood pH levels by transfering specific materials from the peritubular capillaries, back to the tubular filtrate (urine); active transport |
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what substances are usually moved back to filtrate during tubular secretion to control blood pH? |
H+ (hydrogen ions) K+ (potassium) creatinine drugs |
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what does reabsorption mean? |
taking substances out of the filtrate to add to the blood |
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what does secretion mean? |
adding substances to the filtrate by taking them out of the blood |
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what is the pH of urine? |
about 6 |
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what is the appearance of normal urine? |
clear and pale to deep yellow *the normal colour is called urochrome |
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what is glucose in the urine (glycosuria) indicative of? |
diabetes mellitus or excessive intake of sugary food |
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what is pus (WBC's and bacteria) in the urine (pyuria) indicative of? |
a urinary tract infection |
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what is the f(x) of the ureters? |
to carry urine from the kidneys (the renal hilum) to the bladder |
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true or false: the ureters play an active role in urine transport |
true; peristalsis propels urine into the bladder |
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true or false: urine can flow back into the ureters |
false; small valvelike folds of bladder mucosa flap over the ureter openings |
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def renal calculi (singular: calculus) |
kidney stones |
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list 4 favorable conditions for the formation of kidney stones: |
frequent bacterial infections (UTI's);
urinary retention; extremely concentrated urine (where solutes can form crystals); alkaline urine; |
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def trigone: |
the triangular region at the base of the bladder between the openings of the ureters and the urethra |
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what type of epithelium makes up the bladder? |
transitional epithelium |
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what is special about the bladder wall? |
it is three layers of smooth muscle, collectively called the detrusor muscle, that is collapsed when the bladder is empty |
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how much urine is held in a moderately full bladder? |
500mL *the bladder can hold just over twice this amount |
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true or false: the urethra carries urine by peristalsis |
true; the smooth muscle forms the internal urethral sphincter |
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true of false: the internal and the external sphincters are involuntary |
false; the external urethral sphincter is voluntary and formed of skeletal muscle |
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true or false: the urethra in both sexes are of equal size |
false; it's much shorter in women (increased risk of bacterial infections) |
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def urethritis: |
inflammation of the urethra |
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def pyelitis or pyelonephritis: |
kidney inflammation |
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def dysuria: |
painful urination |
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def micturition: |
urination; voiding; emptying the bladder |
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List the 4 steps of the micturition reflex: |
1) the bladder stretches 2) stretch receptors in the wall send impulses to the spinal cord 3) the pelvic splanchnic nerves signal the detrusor muscle to contract rhythmically 4) you feel the need to urinate |
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what sphincter allows control over the timing of urination |
the external one (voluntarily controlled) |
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when a person feels the urge to void, but chooses not to, what occurs? |
contractions of the bladder stop until more urine accumulates (200-300mL) then the cycle repeats until bladder is emptied or until urine can no longer be retained |
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def incontinence: |
loss of bladder control (inability to control external sphincter) |
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true or false: children can void voluntarily by 14 months |
false; until about age 2, children have not yet gained control over their voluntary sphincter *4 years of age for nighttime voluntary control |
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def urinary retention: |
bladder is unable to expel the contained urine *as seen with hyperplasia of the prostate gland |
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what 3 factors affect blood composition? |
diet cellular metabolism urine output |
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true or false: heparin is an anti-coagulant |
true; it prevents clotting |
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list the 4 kidney f(x)'s: |
-excretion of wastes -maintaining water balance -maintaining electrolyte balance -maintaining blood pH |
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what are the major fluid compartments of the body? |
-the intracellular fluid (ICF) -the extracellular fluid (ECF) which is composed of the interstitial fluid (IF) and the plasma |
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what causes water to move from one compartment to another? |
changes in solute/electrolyte concentrations |
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what 3 things does water movement, between compartments, alter? |
-blood pressure -blood volume -activity of nerve and muscle cells |
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def insensible water loss |
unmeasured water loss through: perspiration in skin vaporization in the lungs excreted in stool |
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what is the driving force for water intake? |
the thirst mechanism |
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what happens when there is less water and more solutes in the blood composition? (3 stages) |
-hypothalamic osmoreceptors become more active (in response); -nerve impulses are sent to the posterior pituitary gland; -ADH is released |
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what is the effect of antidiuretic hormone (ADH)? |
this hormone prevents excessive water loss in the urine (making it more concentrated) |
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what gland or organ releases ADH? |
posterior pituitary |
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what is ADH's main target and why? |
the kidney's collecting ducts; to increase the cells water reabsorption |
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what happens when solute concentration of the blood drops too low? |
osmoreceptors go quiet (ADH is no longer released) and excess water is added to urine/filtrate |
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what is diabetes insipidus? what are people who suffer from this at risk for? |
characterized by excessive thirst and excretion of large amounts of severely diluted urine; *affected individuals are at risk for dehydration and electrolyte imbalances |
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def electrolytes |
-a substance that breaks down into ions (charged particles) when in an aqueous solution -capable of conducting an electrical current |
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what electrolyte is most responsible for osmotic water flows? |
the sodium ion (Na+) |
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what happens when there's not enough Na+ in the blood? what does this cause? |
the blood is too dilute, so water leaves the bloodstream and flows into tissue spaces; edema and a possible shutdown of the circulatory system |
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what ion/ions does aldosterone help to regulate within the blood composition? |
mainly the sodium ion content of the ECF, but it also regulates Cl-, K+, and Mg2+ in the process |
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what percent of Na+, in the filtrate, is reabsorbed in the PCT of the kidneys? |
~80% |
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what do high levels of aldosterone cause? |
most of the remaining sodium ions (not reabsorbed into the PCT) are then actively reabsorbed into the DCT and collecting ducts |
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fill in the blanks: |
blood; chloride ion; potassium ion; filtrate; |
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how does aldosterone affect blood volume? |
water follows sodium *think salty=thirsty*; -since aldosterone causes sodium to be reclaimed, water passively follows it back to the blood, therefore increasing blood volume. |
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where is aldosterone produced? |
in the cortex of the adrenal glands |
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what is the most important trigger for aldosterone release? |
renin-angiotensin mechanism |
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what mediates the renin-angiotensin mechanism? |
the juxtaglomerular (JG) apparatus of the renal tubules |
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what do the cells of the JG apparatus release when stimulated? and into where? |
the enzyme renin; the blood |
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what is the purpose of renin? |
it catalyzes a series of reactions that produce angiotensin II |
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what does angiotensin II do? |
It acts directly: -on the blood vessels to cause vasoconstriction (increase in peripheral resistence) and; -on the adrenal cortical cells to promote aldosterone release |
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what is the renin-angiotensin mechanism important for? |
regulating blood pressure (by increasing blood volume and blood pressure) |
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how does the sympathetic nervous system help to regulate blood pressure? |
baroreceptors in larger blood vessels alert the SNS centers of the brain to cause vasoconstriction via release of epinephrine and norepinephrine, which increases peripheral resistance |
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true or false: the neural mechanism's major focus is for blood volume regulation |
false; the major focus is on blood pressure regulation, not water and electrolyte balance |
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def addison's disease (hypoaldosteronism): |
a condition of having decreased levels of the hormone aldosterone *the adrenal glands do not produce sufficient steroid hormones |
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normal range of blood pH |
7.35-7.45 |
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an arterial pH between 7.35-7.0 is called what? |
physiological acidosis *Because a pH of 7.0 is neutral, 7.35 (chemically speaking) is not acidic; however, it represents a higher-than-optimal hydrogen ion concentration |
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def alkalosis: |
increased pH; lower hydrogen ion concentration in the blood than normal |
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where do most hydrogen ions originate from? |
from the by-products of cellular metabolism (which produce many different acids that disturb the acid-base balance) |
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what is the body's first line of defense in resisting pH changes? why? |
blood buffers; they act within a fraction of a second |
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how do chemical buffers work? |
they regulate hydrogen ion (H+) concentration in the blood by releasing H+ ions when pH rises, or by binding to H+ ions when the pH drops |
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true or false: acids are proton H+ donors |
true; acids liberate their H+ ions in water |
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true or false: strong acids dissociate partially in water |
false; strong acids dissociate completely and liberate all of their H+ ions *therefore causing large changes in pH |
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what does it mean to dissociate only partially? |
not all molecules separate; *in acids, H+ ions may still be bound to anions (weak acids) |
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what dissociate easily in water and quickly tie up H+ ions? |
strong bases |
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what happens to weak bases when the pH drops |
the weak bases become stronger and will tie up more H+ ions |
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what are the three major chemical buffers systems of the body? |
bicarbonate; phosphate; protein; |
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what buffer system is most important in preventing changes in blood pH? |
bicarbonate buffer system |
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name the- strong acid: weak base: weak acid: salt: -in the bicarbonate buffer system. |
strong acid: hydrochloric acid (HCl) weak base: sodium bicarbonate (NaHCO3) salt: sodium chloride (NaCl) |
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how does the bicarbonate buffer system work? |
1. when the strong acid is added, the weak acid does not dissociate much 2. the strong acid's loose H+ ions are tied up by the bicarbonate ions of the salt 3. the strong acid is effectively changed to a weak one |
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What form does carbon dioxide take in the blood? |
for transport in the plasma, carbon dioxide is converted to bicarbonate ion (HCO3-) when it enters red blood cells |
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true or false: carbon dioxide is expelled from the lungs at the same rate as it is formed in the tissues |
true; in healthy people the H+ ions produced by CO2 transport have essentially no effect on blood pH |
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How does the respiratory system respond to CO2 accumulation in the blood? |
breathing rate and depth increase; *the excess H+ is 'blown off' |
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how long does it take for respiratory system corrections of blood pH to take place? |
~1 minute. |
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what are the 2 ways that the kidneys maintain the acid-base balance of the blood? |
1. excreting bicarbonate ions 2. conserving (reabsorbing) or generating new bicarbonate ions |
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what is the pH or urine? |
4.5-8.0 pH |
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losing an HCO3- from the body has the same effect as what? |
gaining an H+ *pushes the buffer equation to the right (leaves a free hydrogen ion) |
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def: adult polycystic kidney disease: |
a degenerative condition; one or both kidneys enlarge and have many blisterlike sacs (cysts) containing urine *obstructs, not blocks, urine |
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def hypospadias: |
a condition in males; the urethral orifice is located on the ventral surface of the penis *corrective surgery is done at approx. 12mths old |
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what bacteria causes 80% of UTI's? |
escherichia coli; normal residents of the digestive tract that act as pathogens in the urinary tract |
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def glomerulonephritis: |
a common sequel to untreated childhood strep infections; the glomerular filters become clogged with antigen-antibody complexes (resulting from the strep infection) |
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def urgency: |
a feeling that it is necessary to void |
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def frequency: |
frequent voiding of small amounts of urine |
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def nocturia: |
the need to get up during the night to urinate *plagues almost two-thirds of the population |