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
Angiotensin II formation is suppressed by:
a. Low sodium concentrations and ECF volume
b. Decreased arterial pressure and ECF volume
c. Increased arterial pressure and increased ECF volume
d. a and b
c. Increased arterial pressure and increased ECF volume
A decrease in cardiac output results in:
a. Stimulation of aldosterone release
b. Decrease in angiotensin II production
c. Increase in angiotensin II production
d. Loss of sympathetic nervous system input to kidneys
e. All of the above
f. a and c
g. b and d
f. a and c
Stimulation of aldosterone release and increase in angiotensin II production
Cirrhosis of the liver can lead to:
a. Decreased vascular capacity
b. Increased capillary pressure in portal vascular bed
c. Increased vascular capacity
d. Reduction of plasma proteins
e. a, b, and d
f. b, c and d
g. b and d only
f. b, c and d
(Increased capillary pressure in portal vascular bed, increased vascular capacity
and reduction of plasma proteins)
The “first line of defense” against changes in extracellular fluid potassium concentration is:
a. Increased aldosterone production
b. β-adrenergic stimulation
c. Redistribution between fluid compartments
d. Increased insulin production
c. Redistribution between fluid compartments
Which of the following increase extracellular potassium concentration?
a. Insulin and aldosterone
b. Acidosis
c. Alkalosis
d. Cell lysis
e. Strenuous exercise
f. a and e
g. b and d only
h. b, d and e
h. b, d and e
Acidosis, cell lysis and strenuous exercise
True or False:
Cellular dehydration leads to increased extracellular fluid potassium concentration.
True
Cellular dehydration raises intracellular K concentration favoring a diffusion of potassium out of the cells into the ECF
With elevated potassium intake, returning potassium levels to normal occurs mainly by:
a. Increased secretion of potassium at the proximal tubule
b. Increased secretion at the distal and collecting tubules
c. Decreased reabsorption at the loop of Henle
d. a and b
b. Increased secretion at the distal and collecting tubules
Reabsorption of potassium occurs:
a. Via the hydrogen-potassium ATPase transport in the intercalated cells
b. Via the hydrogen-potassium ATPase transport in the principal cells
a. Via the hydrogen-potassium ATPase transport in the intercalated cells
Aldosterone secretion increases or decreases the rate of potassium excretion.
Increases
PTH increases calcium concentrations by:
a. Increasing calcium reabsorption in the proximal tubule
b. Directly increasing intestinal reabsorption of calcium
c. Stimulating bone reabsorption
d. Decreasing plasma phosphorus
c. Stimulating bone reabsorption
PTH regulates phosphorus concentrations by:
a. Decreasing transport maximum for phosphate in renal tubules, decreasing phosphorus reabsorption
b. Increasing intestinal reabsorption
c. Increasing bone reabsorption
d. a and b
e. b and c
f. a and c
f. a and c
(Decreasing transport maximum for phosphate in renal tubules, decreasing phosphorus reabsorption and increasing bone reabsorption)
The kidneys regulate ECF hydrogen ion concentration through 3 mechanisms:
a. _____________________
b. _____________________
c. _____________________
a. secretion of hydrogen ions
b. reabsorption of filtered bicarbonate ions
c. production of new bicarbonate ions
Primary active secretion of hydrogen ions occurs:
a. In principal cells of collecting tubules
b. In the proximal tubule
c. In the loop of Henle
d. In the late distal and collecting tubules via intercalated cells
d. In the late distal and collecting tubules via intercalated cells
True or False:
In the tubular fluid, when all the bicarbonate is reabsorbed, excess hydrogen ions can combine with either phosphate or ammonium ion and no net bicarbonate is produced.
False.
Whenever a hydrogen ion secreted into the tubular lumen combines with a buffer other than bicarbonate, the net effect is addition of a new bicarbonate ion to the blood.
The following disease processes does not induce a metabolic acidosis:
a. Vomiting of gastric contents
b. Chronic renal failure
c. Renal tubular failure to reabsorb bicarbonate
d. Diabetes mellitus
a. Vomiting of gastric contents
Which of the following is NOT a mechanism by which angiotensin II increases arterial blood pressure?
a. Vasoconstriction of arterioles leading to increased total peripheral resistance
b. Vasoconstriction of veins promoting increased venous return to the heart
c. Decreased renal salt and water excretion leading to increased extracellular fluid volume
d. Stimulation of the thirst center leading to increased extracellular fluid volume
d. Stimulation of the thirst center leading to increased extracellular fluid volume
Which solute has little to no effect on tonicity?
a. Sodium
b. Urea
c. Glucose
d. Chloride
b. Urea
Which substances contribute to the effective plasma osmolality (tonicity)?
a. Chloride, urea, sodium
b. Urea, potassium, sodium
c. Sodium, glucose, chloride
d. Glucose, chloride, potassium
c. Sodium, glucose, chloride
Which of the following electrolytes has the highest urine concentration?
a. Na
b. K
c. Cl
d. P
b. K
Which of the following will not result in metabolic acidosis when added to the diet in ruminants, and thus is not considered an “anionic salt”?
a. HCl
b. NaCl
c. MgCl
d. CaCl
e. NH3Cl
b. NaCl
Which of the following will not correct metabolic alkalosis?
a. HCl
b. NaCl
c. Na-lactate
d. KCl
c. Na-lactate
Which of the following statements regarding the Standard Bicarbonate concentration is correct?
a. Is the temperature-corrected (37* C) actual Bicarbonate concentration in plasma
b. Is the bicarbonate concentration corrected to normal , the normal pCO2 at 37* C
c. Is the bicarbonate concentration corrected to normal, the normal pCO2 at 37* C and plasma protein concentration of 5.2 mg/dL
d. Is less accurate than the actual bicarbonate concentration to determine severity of metabolic acidosis.
b. Is the bicarbonate concentration corrected to normal , the normal pCO2 at 37* C
Which of the following does not result in hyperkalemia?
a. Metabolic acidemia
b. Diabetes mellitus
c. Hyperosmolality
d. Diabetes insipidus
a 70
What is the predominant phosphorus-containing compound in plasma at physiologic blood pH?
a. H3PO4
b. HPO4
c. H2PO4
d. HPO3
e. H2PO3
b 71
- Which of the following parameters is most correlated with the development of hypokalemia in diarrheic calves 24 hours after admission to hospital?
a) Acute onset of severe diarrhea
b) Higher milk intake during hospitalization
c) Metabolic acidosis on admission
d) Metabolic alkalosis at 24 hours
c) Metabolic acidosis on admission
The primary cause of metabolic acidosis in diarrheic calves is which of the following?
a) Increase in strong cations relative to anions
b) Fecal loss of bicarbonate
c) Lactate production due to poor perfusion
d) Lactate due to abnormal bacterial fermentation
d) Lactate due to abnormal bacterial fermentation
Type 2 and Type 3 vagal indigestion is best differentiated by which of the following?
a) Severity of hypochloremia
b) Abdominal contour
c) Severity of metabolic acidosis
d) Abdominal percussion
a) Severity of hypochloremia
Activation of the Renin-Angiotensin-Aldostrone system results in which of the following?
a) Sodium and water loss with vasoconstriction and a net increase in blood pressure
b) Sodium and water loss with vasodilation and a net decrease in blood pressure
c) Sodium and water retention with vasoconstriction and a net increase in blood pressure
d) Sodium and water retention with vasodilation and a net decrease in blood pressure
c) Sodium and water retention with vasoconstriction and a net increase in blood pressure
Which of the following statements is CORRECT regarding renal tubular acidosis (RTA) in the horse?
a) Type I RTA results from an impaired excretion of bicarbonate in the distal tubules.
b) Type I RTA can be diagnosed by the presence of acidosis and concurrent aciduria.
c) Type II RTA results from an inability of the proximal tubules to reabsorb bicarbonate.
d) Type II RTA typically presents with a hypochloremic metabolic acidosis.
c) Type II RTA results from an inability of the proximal tubules to reabsorb bicarbonate.
Which of the following desribes the correct site of action of carbonic anhydrase inhibitors?
a) Descending loop of Henle
b) Distal convoluted tubule
c) Glomerulus
d) Proximal convoluted tubule
d) Proximal convoluted tubule
Which of the following ions is not considered a strong ion in Stewart’s strong ion approach?
a. Na
b. K
c. P
d. Cl
e. Lactate
a. Na
Which of the following is not part of the mechanisms through which the kidney regulates acid-base homeostasis?
a. Increased HCO3 reasbsorption
b. Increased NH4 synthesis
c. Increased K excretion
d. Increased P excretion
c. Increased K excretion
Which of the following is not a clinically recognized cause of hypokalemia?
a. Excess renal K loss
b. Vomiting
c. Hypomagnesemia
d. Hypocalcemia
d. Hypocalcemia
Nodular dermatofibrosis is a paraneoplastic syndrome that is most associated with which of the following malignancies:
a. Renal hemangiosarcoma
b. Renal cystadenocarcinoma
c. Renal tubular cell carcinoma
d. Renal nephroblastoma
b. Renal cystadenocarcinoma
- ADH increases expression of aquaporin 2 in which part of the nephron?
a. Luminal surface of DCT and collecting ducts
b. Luminal surface of PCT
c. Basolateral surface of DCT and collecting ducts
d. Basolateral surface pf PCT
a. Luminal surface of DCT and collecting ducts
The filtration barrier of the glomerulus is made up of 3 layers. Which of the following is not one of these layers?
a. Fenestrated endothelium
b. Mesangial cell
c. Glomerular basement membrane
d. Visceral epithelial cell (also known as podocytes)
b. Mesangial cell
Which of the following variables is NOT a significant determinant of glomerular hydrostatic pressure?
a. Arterial pressure
b. Central venous pressure
c. Afferent arteriolar resistance
d. Efferent arteriolar ressitance
b. Central venous pressure
12Which of the following is FALSE regarding the renin-angiotensin system?
a. Activation of the renin-angiotensin system can lead to significant decreases in urine output due to renal arteriole constriction
b. Angiotensin directly induces the tubular cells to increase tubular reabsorption of Na and water
c. The conversion of angiotensin I to angiotensin II occurs primarily within the walls of the arterioles of the kidney
d. Angiotensin II causes more significant vasoconstriction within the arterioles than the veins.
c. The conversion of angiotensin I to angiotensin II occurs primarily within the walls of the arterioles of the kidney
Hypercalcemia causes renal failure by all of the following mechanisms EXCEPT:
A. Impaired sodium resorption in the proximal convoluted tubule leading to polyuria, hypovolemia and ischemia renal injury.
B. Vasoconstriction of the afferent arteriole leading to ischemic renal injury
C. Impaired aquaporin assembly in the distal convoluted tubule and collecting duct, leading to polyuria, hypovolemia and ischemic renal injury
D. Direct injury to renal tubular epithelial cells via increased intracellular Ca concentration
E. Centrally-medially adipsia, leading to volume depletion and ischemic renal injury.
A. Impaired sodium resorption in the proximal convoluted tubule leading to polyuria, hypovolemia and ischemia renal injury.
Which of the following is true regarding Reynold’s number and the propensity for turbulence?
A. As the diameter of the vessel increases, the propensity for turbulence decreases
B. As the density of blood decreases, the propensity for turbulence increases
C. As the viscosity of the blood decreases, the propensity for turbulence does not change
D. As the velocity of blood flow increases, the propensity for turbulence increases
D. As the velocity of blood flow increases, the propensity for turbulence increases
Which nerve transmits parasympathetic impulses to the urinary bladder wall and to muscarinic receptors in the detrusor smooth muscle?
A. Pelvic nerve
B. Pudendal nerve
C. Hypogastric nerve
D. Caudal epigastric nerve
A. Pelvic nerve
Which of the following statements is incorrect?
A. The fractional excretion of an electrolyte is the renal excretion of this electrolyte expressed as a percentage of the renal creatinine excretion
B. The fractional excretion of an electrolyte is the percentage of filtered electrolyte that is excreted in urine
C. Expressing the renal excretion of an electrolyte as FE removes the confounding effect of changes in free water excretion
D. Fractional excretion of an electrolyte is confounded by changes of the glomerular filtration rate
D. Fractional excretion of an electrolyte is confounded by changes of the glomerular filtration rate
Which of the following is the best estimate of glomerular filtration rate?
A. Creatinine concentration in urine
B. Endogenous creatinine clearance
C. Fractional excretion of potassium
D. Urine potassium: creatinine ratio
B. Endogenous creatinine clearance
Which of the following does not alter renal phosphate handling?
A. Hypophosphatemia B. Hyperinsulinemia C. Metabolic acidosis D. PTH E. Calcitrol
B. Hyperinsulinemia
Which of the following abnormalities does not cause metabolic acidosis?
A. Hyperchloremia B. Hyperlactatemia C. Hyperproteinemia D. Hyperkalemia E. Hypercalcemia
E. Hypercalcemia
Which of the following does not cause metabolic alkalosis?
A. Vomiting B. Hypokalemia C. Chloride-loosing diarrhea D. Antiacid Therapy E. Treatment with hypertonic saline
E. Treatment with hypertonic saline
Distribution of potassium between the intra-cellular space and the extra-cellular space provide a first line of defense against changes in the concentration of potassium in the extracellular fluid. Which of the following factors will shift potassium into the cells:
a. Acidosis
b. Increased extracellular fluid osmolarity
c. Aldosterone
d. Addison’s disease
c. Aldosterone
The “diluting segment” of the nephron includes:
a. The proximal tubule and descending limb of the loop of Henle
b. The descending and thin ascending limbs of the loop of Henle
c. The thick ascending limb of the loop of Henle and the distal tubule
d. The distal tubule and the collecting duct
c. The thick ascending limb of the loop of Henle and the distal tubule
The best measure of renal function is:
a. Urine output
b. Serum creatinine concentration
c. Glomerular filtration rate
d. Urine osmolality
c. Glomerular filtration rate
Antidiuretic hormone (ADH) is released in response to:
a. Thirst
b. An increase in plasma osmolality
c. An increase in plasma glucose concentration
d. Drinking a large amount of water
e. Drinking a large amount of beer after this exam
b. An increase in plasma osmolality
