Renal & Acid base Flashcards
Renal tubular acidosis types I and II have been described in the horse. Which of the following best describes each type:
a. Type I: tubules unable to reabsorb bicarbonate ions; Type II: tubules unable to excrete hydrogen ions
b. Type I: tubules unable to excrete hydrogen ions; Type II: tubules unable to reabsorb bicarbonate ions
c. Type I: Hyperkalemia due to primary hypoaldosteronism; Type II: tubules unable to reabsorb bicarbonate ions
d. Type I: tubules unable to reabsorb bicarbonate ions; Type II: hyperkalemia due to aldosterone resistance
b. Type I: tubules unable to excrete hydrogen ions; Type II: tubules unable to reabsorb bicarbonate ions
Type I - Distal renal tubular acidosis. Not capable of lowering urine pH normally, there is excessive back diffusion of H+ ions from lumen into blood. There is also a secondary impairment of NH4+ secretion.
Type II - Proximal renal tubular acidosis. Proximal cells are unable to reabsorb bicarbonate resulting in bicarbonate loss in urine. Defective re-absorption of glucose, aa, electrolytes and organic acids can also occur.
The most significant contributor to metabolic acidosis in calves with diarrhea is which of the following:
a. Hypochloremia due to abomasal sequestration
b. D-lactate due to aberrant gut flora proliferation
c. L-lactate due to hypoxia and poor perfusion
d. Intestinal bicarbonate loss
b. D-lactate due to aberrant gut flora proliferation
Which of the following alterations in strong ion difference (SID) and anion gap (AG) would be expected
in a horse with proximal enteritis of 18 hours duration that had not yet been treated?
A. Decreased [SID]; increased AG
B. Decreased [SID]; normal AG
C. Increased [SID]; increased AG
D. Increased [SID]; normal AG
C. Increased [SID]; increased AG
Ref: Smith LAIM 4th Ed 2009. p389.
In the tubules, urea is:
a. Actively excreted
b. Passively reabsorbed by following water
c. Poorly permeable and is not reabsorbed at all
d. Passively reabsorbed by following a concentration gradient
b. Passively reabsorbed by following water
Proximal tubule cells have a high capacity for active and passive reabsorption due to:
Proximal tubule epithelial cells are highly metabolic and have large numbers of mitochondria.
Also, proximal tubule cells have extensive membrane surface area on luminal and basolateral sides of epithelium.
In the ascending loop of Henle, water permeability is always:
a. High
b. Low
c. Moderated by ADH
d. Both b and c
b. Low
Chloride reabsorption in the tubules is accomplished by:
a. Passive mechanisms such as by concentration gradient
b. Active mechanisms
c. Electrical potential
d. All of the above
e. a and c only
d. All of the above
Passive mechanisms such as by concentration gradient, active mechanisms and electrical potential
In the proximal tubules, sodium reabsorption happens by:
a. Counter-transport with hydrogen ions
b. Co-transport with glucose and amino acids
c. Counter-transport with chloride ions
d. Co-transport with chloride ions
e. b and d
f. a and c
e. b and d
Co-transport with glucose and amino acids and co-transport with chloride ions
The tubular fluid that reaches the distal tubule:
a. Is concentrated due to ADH action
b. Is dilute due to impermeability of the thick segment of the L.O.H.to water
c. Has a high concentration of Mg and calcium ions
d. Has a slightly negative charge
b. Is dilute due to impermeability of the thick segment of the L.O.H.to water
The thin descending segment of the loop of Henle:
a. Is somewhat permeable to water and highly permeable to solute
b. Allows simple diffusion due to its simplified structure
c. Reabsorbs most of the filtered water
d. None of the above
e. b and c
e. b and c
Allows simple diffusion due to its simplified structure and reabsorbs most of the filtered water
In the thick ascending segment, magnesium and calcium ions:
a. Diffuse with water paracellularly
b. Are actively reabsorbed
c. Are co-transported with sodium due to a backleak of potassium ions
d. Diffuse paracellularly due to a slight positive charge in the lumen
d. Diffuse paracellularly due to a slight positive charge in the lumen
Principal and intercalated cells are found in:
a. Distal tubule and cortical collecting tubules
b. Thick segment of ascending loop of Henle
c. Late distal tubule and cortical collecting tubules
d. Early distal tubule and late distal tubule
e. c and d
c. Late distal tubule and cortical collecting tubules
Which statement(s) about the medullary collecting duct is/are False?
a. Contributes to acid-base balance
b. Has high osmotic pressure in its interstitium
c. Reabsorbs sodium and hydrogen ions
d. Responds to ADH
e. Is permeable to urea
c. Reabsorbs sodium and hydrogen ions
Which statement(s) about intercalated cells is/are True?
a. Are found in the early distal tubule
b. Secrete potassium and hydrogen ions
c. Reabsorb potassium and secrete hydrogen ions
d. Play a role in acid-base balance
e. a and c
f. c and d
f. c and d
Reabsorb potassium, secrete hydrogen ions and play a role in acid-base balance
Which statements about principal cells is/are False?
a. Are found in the late distal and cortical collecting tubules
b. Reabsorb sodium and potassium ions from the lumen
c. Minimally responsive to ADH
d. Potassium diffuses down concentration gradient to tubular lumen
e. a and d
f. b and c
e. a and d
(Are found in the late distal and cortical collecting tubules.
Potassium also diffuses down concentration gradient to tubular lumen)
Which of the following statements is/are True?
a. Aldosterone primarily acts on intercalated cells of the cortical collecting tubule
b. Inhibition of aldosterone results in sodium accumulation and excessive potassium loss
c. Aldosterone acts on the sodium-potassium ATPase pump on the basolateral side of the cortical collecting tubule membrane
d. All of the above
e. a and c
f. b and c
c. Aldosterone acts on the sodium-potassium ATPase pump on the basolateral side of the cortical collecting tubule membrane
Which of the following statements is/are False?
a. Parathyroid hormone and angiotensin II act on the proximal tubules
b. ADH acts on the loop of Henle and distal tubule
c. Aldosterone increases sodium permeability of the tubule membrane
d. All of the above
e. b and c
b. ADH acts on the loop of Henle and distal tubule
Which of the following statements is/are True?
a. Angiotensin II stimulates aldosterone secretion
b. PTH reduces reabsorption of calcium and increases reabsorption of phosphorus
c. Angiotensin II constricts efferent arterioles
d. All of the above
e. a and c
f. a and b
e. a and c
Angiotensin II stimulates aldosterone secretion and constricts efferent arterioles
The medullary interstitium is made ___________ by the reabsorption of __________ without _________ in the ascending loop of Henle.
a. Hypoosmotic, water, NaCl
b. Hypoosmotic, NaCl, water
c. Hyperosmotic, NaCl, water
d. Hyperosmotic, water, NaCl
c. Hyperosmotic, NaCl, water
The interstitium osmolality at the papillary tip is directly proportional to:
a. Urea and NaCl active transport
b. Length of the loops and gradient between the ascending limb and interstitium
c. ADH activity
d. All of the above
e. A and c
b. Length of the loops and gradient between the ascending limb and interstitium
True or False:
Angiotensin II and aldosterone have no direct effect on serum NaCl concentration.
TRUE
Final urine osmolality is determined by:
a. Events in loop of Henle
b. Water permeability of collecting tubules
c. Urea concentration
d. Aldosterone activity
b. Water permeability of collecting tubules
The collecting tubules are permeable or impermeable to urea. _______________
Impermeable
In the absence of ADH, urea accumulation in the interstitium is ____________.
a. Reduced
b. Increased
c. Unaffected
a. Reduced
Nephrogenic diabetes inspidus can be caused by:
a. Lack of production of ADH
b. Reduced response to ADH
c. Medullary washout
d. All of the above
e. a and c
f. b and c
f. b and c
Reduced response to ADH, and medullary washout
Increased blood flow through the vasa recta will ________ solute concentration in the medullary interstitium.
a. Increase
b. Decrease
c. Not affect
b. Decrease
A(n) _________ in plasma sodium concentration will cause osmoreceptor cells to shrink.
a. Has no effect.
b. Decrease
c. Increase
c. Increase
Which hormone or mechanism is the most effective in regulating plasma osmolality?
a. Aldosterone
b. Angiotensin II
c. ADH-thirst mechanism
d. Changes in blood volume
c. ADH-thirst mechanism
Vasodilation and increased GFR increases NaCl delivery to the tubules, which prompts what 2 intrarenal compensations?
Glomerulotubular balance and macula densa feedback.
In terms of pressure natriuresis, a _______ _______ in blood pressure is required to raise urinary excretion several fold.
a. significant increase
b. slight increase
b. slight increase
During hemorrhage, reflex activation the renal sympathetic nervous system results in:
a. ____________________
b. ____________________
c. ____________________
a. constriction of the renal arterioles, resulting in decreased GFR
b. increased tubular reabsorption of salt and water
c. stimulation of renin release and increased angiotensin II and aldosterone formation
A large increase in sodium intake causes a(n) increase or decrease in angiotensin II formation.
Decrease
True or False:
Elevated levels of ADH can increase sodium ion concentrations.
False
Causes a decrease in sodium ion concentrations due to water reabsorption and dilution of extracellular sodium and the concurrent rise in blood pressure induces pressure natriuresis and subsequent loss of sodium in the urine