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17 Cards in this Set
- Front
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2. Percy is suffering from secondary hypercortisolism due to ACTH being secreted by tumor cells on his lung. Which one of the following would best describe what you would observe in Percy?
ACTH levels CRH levels Cortisol levels Plasma proteins A high high high high B low low high high C high high high low D high low high high E high low high low |
2. Percy is suffering from secondary hypercortisolism due to ACTH being secreted by tumor cells on his lung. Which one of the following would best describe what you would observe in Percy?
ACTH levels CRH levels Cortisol levels Plasma proteins A high high high high B low low high high C high high high low D high low high high E high low high low The answer is D. ACTH is being uncontrollably secreted so its levels will be high. The hypercortisolism will decrease CRH levels. It is hypercortisolism due to ACTH so cortisol levels will be high. Cortisol stimulates plasma protein synthesis by the liver so they will be increased |
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3. The partial pressure of oxygen in the umbilical artery is much lower than that of the uterine artery. The major reason for this low partial pressure is:
A The hemoglobin affinity is greater in the umbilical artery B The umbilical artery is leaving the fetus C The amount of dissolved oxygen is less in the umbilical artery D There is more hemoglobin in the fetal circulation E The oxygen content of the umbilical vein is greater than the umbilical artery |
3. The partial pressure of oxygen in the umbilical artery is much lower than that of the uterine artery. The major reason for this low partial pressure is:
A The hemoglobin affinity is greater in the umbilical artery B The umbilical artery is leaving the fetus C The amount of dissolved oxygen is less in the umbilical artery D There is more hemoglobin in the fetal circulation E The oxygen content of the umbilical vein is greater than the umbilical artery The answer is C. This is a tricky question to read. What I have done is added material from one section to answer a question from another. The question is a partial pressure question not one associated with the uterine/umbilical circulation. It is simple fact that the partial pressure of oxygen in the blood is determined by the amount of dissolved oxygen. Therefore if the umbilical artery has a lower partial pressure it MUST have a lower amount of dissolved oxygen. |
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2. In a normal kidney which of the following conditions would cause an increase in the
glomerular filtration rate(GFR)? A. constriction of the afferent arteriole B. a decrease in the hydrostatic pressure of the glomerulus C. an increase in the capsular hydrostatic pressure D. a decrease in the concentration of plasma proteins in the blood |
2. In a normal kidney which of the following conditions would cause an increase in the
glomerular filtration rate(GFR)? A. constriction of the afferent arteriole B. a decrease in the hydrostatic pressure of the glomerulus C. an increase in the capsular hydrostatic pressure D. ***a decrease in the concentration of plasma proteins in the blood |
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5. The primary stimulus which affects the secretion of ADH is __?
A. plasma osmolarity B. blood pressure C. blood volume D. renin release E. urine flow |
5. The primary stimulus which affects the secretion of ADH is __?
A. *plasma osmolarity B. blood pressure C. blood volume D. renin release E. urine flow |
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8. David has a glomerular filtration rate (GFR) of 120ml/min. You measure the clearance
rate of the freely filtered Substance X and find a value of 230ml/min. Which one of the following can you state regarding Substance X? A. There is no secretion or reabsorption of Substance X. B. There is net secretion of Substance X. C. There is net reabsorption of Substance X. D. Substance X must be an anion. |
8. David has a glomerular filtration rate (GFR) of 120ml/min. You measure the clearance
rate of the freely filtered Substance X and find a value of 230ml/min. Which one of the following can you state regarding Substance X? A. There is no secretion or reabsorption of Substance X. B. *There is net secretion of Substance X. C. There is net reabsorption of Substance X. D. Substance X must be an anion. |
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Sodium reabsorption from the distal tubule will be increased if there
is an increase in a. Plasma potassium concentration b. Plasma volume c. Mean arterial pressure d. Urine flow rate e. Plasma osmolality |
The answer is a. (Guyton, pp 369, 340–341, 872–873.) Sodium
(Na+) reabsorption in the distal nephron is controlled primarily by aldosterone. Increases in plasma aldosterone concentration increase Na+ reabsorption. Aldosterone secretion is increased when plasma concentrations of angiotensin II or potassium (K+) are increased. Increases in plasma volume or mean arterial pressure will lead to a decrease in angiotensin II secretion. Increases in plasma osmolality will cause an increase in ADH. ADH will decrease water excretion but have only a minimal effect on sodium reab |
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Renin secretion by the kidney is increased by
a. Increasing mean blood pressure b. Increasing glomerular filtration rate c. Increasing sympathetic nerve activity d. Increasing angiotensin II synthesis e. Increasing atrial natriuretic hormone secretion |
Renin secretion by the kidney is increased by
a. Increasing mean blood pressure b. Increasing glomerular filtration rate c. Increasing sympathetic nerve activity d. Increasing angiotensin II synthesis e. Increasing atrial natriuretic hormone secretion The answer is c. (Rhoades, pp 421–422, 453–455, 697–699.) Renin secretion is stimulated by the sympathetic nerves innervating the juxtaglomerular apparatus. Increasing mean blood pressure decreases sympathetic activity. Changes in GFR are detected by the macula densa. Decreases in GFR lead to an increase in renin release and the secretion of a mediator, perhaps adenosine, that contracts the afferent arteriole. ANF and angiotensin II will decrease renin release. |
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The daily production of hydrogen ion from CO2 is primarily buffered
by a. Extracellular bicarbonate b. Red blood cell bicarbonate c. Red blood cell hemoglobin d. Plasma proteins e. Plasma phosphate |
The daily production of hydrogen ion from CO2 is primarily buffered
by a. Extracellular bicarbonate b. Red blood cell bicarbonate c. **Red blood cell hemoglobin d. Plasma proteins e. Plasma phosphate |
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The secretion of H+ in the proximal tubule is primarily associated
with a. Excretion of potassium ion b. Excretion of hydrogen ion c. Reabsorption of calcium ion d. Reabsorption of bicarbonate ion e. Reabsorption of phosphate ion |
The secretion of H+ in the proximal tubule is primarily associated
with a. Excretion of potassium ion b. Excretion of hydrogen ion c. Reabsorption of calcium ion d. **Reabsorption of bicarbonate ion e. Reabsorption of phosphate ion |
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Use the following laboratory values to answer the next two questions.
PAH clearance = 750 mL/min Urinary flow = 2 mL/min Plasma creatinine Plasma glucose concentration = 0.8 mg/dL concentration = 120 mg/dL Urinary creatinine concentration = 66 mg/dL 300. What is the patient’s filtration fraction? a. 0.18 b. 0.20 c. 0.22 d. 0.24 e. 0.26 Renal and Acid-Base Physiology 199 301. Approximately how much glucose is reabsorbed by this patient’s kidneys? a. 0 mg/min b. 120 mg/min c. 165 mg/min d. 200 mg/min e. 320 mg/min |
The answers are 300-c, 301-d. (Guyton, pp 309–312.) The
filtration fraction is the fraction of plasma filtered from the plasma flowing through the kidney, or GFR/RPF. Renal plasma flow is equal to the clearance of PAH; GFR is equal to the clearance of creatinine. Clearance of creatinine can be calculated using the following formula: Ccr = [Ucr × ˙V ] ÷ Pcr = [66 × 2] ÷ 0.8 = 165 mL/min Renal and Acid-Base Physiology Answers 221 Thus, the filtration fraction is 165/750 = 0.22. At glucose concentrations below 150 to 200 mg/dL, the kidneys will reabsorb all the glucose passing through the kidney. The filtered load of glucose is Pglu × GFR = 120 mg/dL × 165 mL/min = 198 mg/min. Since all of this will be reabsorbed, the kidneys reabsorb approximately 200 mg of glucose per minute. |
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Use the following laboratory values to answer the questions.
Urinary volume = 1.5 L/day Urinary [NH4 +] = 20 meq/L Urinary [HCO3 −] = 4 meq/L Urine pH = 6.5 Urinary titratable Plasma pH = 7.3 acids = 10 meq/L urine 302. What is the daily net acid excretion for this patient? a. 51 meq/day b. 39 meq/day c. 34 meq/day d. 30 meq/day e. 26 meq/day |
Net acid excretion is equal to the sum of the amount of titratable
acids plus the amount of the ammonium ions minus the amount of bicarbonate ions contained in the volume of urine produced per day. Net acid excretion = ([titratable acids] + [NH4 +] − 2 [HCO3 −]) × urine volume per day = (10 meq/L + 20 meq/L − 4 meq/L) × 1.5 L/day = 39 meq/day Acid is excreted in urine bound to titratable acids, principally phosphates, and bound to ammonia as NH4 +. If bicarbonate is present in urine, its amount must be subtracted because a bicarbonate ion excreted in the urine means that a hydrogen ion was left behind in the body. Conversely, a net hydrogen ion excreted means that a bicarbonate ion was left behind in the body. Thus, net acid excretion is equal to new bicarbonate formation. |
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The pH of the tubular fluid in the distal nephron can be lower than
that in the proximal tubule because a. A greater sodium gradient can be established across the wall of the distal nephron than across the wall of the proximal tubule b. More buffer is present in the tubular fluid of the distal nephron than in the proximal tubule c. More hydrogen ion is secreted into the distal nephron than into the proximal tubule d. The brush border of the distal nephron contains more carbonic anhydrase than that of the proximal tubule e. The tight junctions of the distal nephron are less leaky to solute than those of the proximal tubule |
The pH of the tubular fluid in the distal nephron can be lower than
that in the proximal tubule because a. A greater sodium gradient can be established across the wall of the distal nephron than across the wall of the proximal tubule b. More buffer is present in the tubular fluid of the distal nephron than in the proximal tubule c. More hydrogen ion is secreted into the distal nephron than into the proximal tubule d. The brush border of the distal nephron contains more carbonic anhydrase than that of the proximal tubule e. **The tight junctions of the distal nephron are less leaky to solute than those of the proximal tubule |
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Renal correction of hyperkalemia will result in
a. Alkalosis b. Acidosis c. Increased secretion of HCO3 − d. Increased secretion of H+ e. Increased excretion of Na+ |
Renal correction of hyperkalemia will result in
a. Alkalosis b.** Acidosis c. Increased secretion of HCO3 − d. Increased secretion of H+ e. Increased excretion of Na+ |
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Which of the following structural features distinguishes the epithelial
cells of the proximal tubule from those of the distal tubule? a. The distal tubule has a thicker basement membrane b. The proximal tubule has a thicker basement membrane c. The proximal tubule has a more extensive brush border d. The proximal tubule forms the juxtaglomerular apparatus e. The distal tubule has fewer tight intercellular junctions |
Which of the following structural features distinguishes the epithelial
cells of the proximal tubule from those of the distal tubule? a. The distal tubule has a thicker basement membrane b. The proximal tubule has a thicker basement membrane c. The proximal tubule has a more extensive brush border d. The proximal tubule forms the juxtaglomerular apparatus e. The distal tubule has fewer tight intercellular junctions The answer is c. (Guyton, pp 300–305.) The major structural differences between epithelial cells of the proximal and distal tubules account for the fact that 65% of glomerular filtrate is reabsorbed in the proximal tubule and that the proximal tubule is more permeable to water. The proximal tubule has an extensive brush border composed of numerous microvilli, which markedly increase the surface area for reabsorption, and the tubule also has an extensive network of intracellular channels. The distal tubule has many more tight junctions between cells, which makes it less permeable to water. No significant difference in basement membrane thickness is observed between the proximal and distal tubules. The juxtaglomerular apparatus is formed |
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Which of the following statements concerning the renal handling of
proteins is correct? a. Proteins are more likely to be filtered if they are negatively charged than if they are uncharged b. Proteins can be filtered and secreted but not reabsorbed by the kidney c. Most of the protein excreted each day is derived from tubular secretion d. Protein excretion is directly related to plasma protein concentration e. Protein excretion is increased by sympathetic stimulation of the kidney |
Which of the following statements concerning the renal handling of
proteins is correct? a. Proteins are more likely to be filtered if they are negatively charged than if they are uncharged b. Proteins can be filtered and secreted but not reabsorbed by the kidney c. Most of the protein excreted each day is derived from tubular secretion d. Protein excretion is directly related to plasma protein concentration e. ***Protein excretion is increased by sympathetic stimulation of the kidney |
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Activation of hormone-sensitive lipase in adipocytes
a. Causes increased hydrolysis of cholesterol esters b. Is mediated by a cyclic AMP–dependent protein kinase c. Is prevented by cortisol d. Is stimulated by insulin e. Results in accumulation of monoglycerides and diglycerides in adipocytes |
Activation of hormone-sensitive lipase in adipocytes
a. Causes increased hydrolysis of cholesterol esters b. **Is mediated by a cyclic AMP–dependent protein kinase c. Is prevented by cortisol d. Is stimulated by insulin e. Results in accumulation of monoglycerides and diglycerides in adipocytes glucagon - HSL insulin LPL |
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The effects of primary hyperaldosteronism (Conn’s syndrome) include
a. Hypertension b. Hyperkalemia c. Decreased extracellular fluid volume d. Increased concentrating ability of the kidney e. Increased hematocrit |
The effects of primary hyperaldosteronism (Conn’s syndrome) include
a. **Hypertension b. Hyperkalemia c. Decreased extracellular fluid volume d. Increased concentrating ability of the kidney e. Increased hematocrit |
