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Question 1
Correct
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An important enzyme in renal tissue responsible for the conversion of glutamine to glutamate and the subsequent production of NH4 is called?
Your Answer: Glutaminase
Explanation:Glutaminase catalyses the following reaction:Glutamine + H2O → Glutamate + NH3
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This question is part of the following fields:
- Medicine
- Renal
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Question 2
Correct
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An effect of aging on the kidney includes?
Your Answer: Decreased GFR
Explanation:The normal range of GFR, adjusted for body surface area, is 100 to 130 mL/min/1.73m2 in men and 90 to 120 ml/min/1.73m2 in women younger than the age of 40. After age 40, GFR decreases progressively with age, by about 0.4 mL/min to 1.2 mL/min per year.
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This question is part of the following fields:
- Medicine
- Renal
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Question 3
Correct
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Amino acid reabsorption occurs most markedly in the?
Your Answer: Proximal convoluted tubule
Explanation:Renal protein reabsorption is the part of renal physiology that deals with the retrieval of filtered proteins, preventing them from disappearing from the body through the urine. Almost all reabsorption takes place in the proximal tubule. Only ,1% is left in the final urine.
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This question is part of the following fields:
- Medicine
- Renal
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Question 4
Correct
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Renin is secreted by which of the following cells?
Your Answer: Juxtaglomerular cells
Explanation:The juxtaglomerular cells are cells in the kidney that synthesize, store, and secrete the enzyme renin. They are specialized smooth muscle cells mainly in the walls of the afferent arterioles, and some in the efferent arterioles, that deliver blood to the glomerulus.
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This question is part of the following fields:
- Medicine
- Renal
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Question 5
Correct
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Where is angiotensinogen produced?
Your Answer: Liver
Explanation:Angiotensin is a peptide hormone that causes vasoconstriction and a subsequent increase in blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex. Aldosterone promotes sodium retention in the distal nephron, in the kidney, which also drives blood pressure up. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver.
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This question is part of the following fields:
- Medicine
- Renal
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Question 6
Correct
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Where is most of the filtered sodium reabsorbed?
Your Answer: Proximal tubule
Explanation:Renal reabsorption of sodium (Na+) is a part of renal physiology. It uses Na-H antiport, Na-glucose symport, sodium ion channels (minor). It is stimulated by angiotensin II and aldosterone, and inhibited by atrial natriuretic peptide. Most of the reabsorption (65%) occurs in the proximal tubule.
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This question is part of the following fields:
- Medicine
- Renal
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Question 7
Correct
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Glucose is typically removed from the urine by…?
Your Answer: Secondary active transport
Explanation:Glucose, amino acids, inorganic phosphate, and some other solutes are resorbed via secondary active transport through co-transporters driven by the sodium gradient out of the nephron.
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This question is part of the following fields:
- Medicine
- Renal
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Question 8
Correct
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Which of the following is the correct way to calculate the anion gap?
Your Answer: (Na + K) – (HCO3 + Cl)
Explanation:The anion gap is the difference between the measured cations (positively charged ions) and the measured anions (negatively charged ions) in serum, plasma, or urine. The magnitude of this difference in the serum is often calculated in medicine when attempting to identify the cause of metabolic acidosis. Anion Gap = ([Na+] + [K+]) − ([Cl−] + [HCO−3])
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This question is part of the following fields:
- Medicine
- Renal
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Question 9
Correct
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What effect does osmotic diuresis have on net Na+ excretion?
Your Answer: Markedly increased Na+ excretion
Explanation:Osmotic diuresis is the increase of urination rate caused by the presence of certain substances in the small tubes of the kidneys. The excretion occurs when substances such as glucose enter the kidney tubules and cannot be reabsorbed (due to a pathological state or the normal nature of the substance). The substances cause an increase in the osmotic pressure within the tubule, causing retention of water within the lumen, and thus reduces the reabsorption of water, increasing urine output (i.e. diuresis). Sodium, chloride, potassium are markedly excreted in osmotic diuresis.
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This question is part of the following fields:
- Medicine
- Renal
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Question 10
Correct
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How does the proximal convoluted tubule excrete H+?
Your Answer: Via Na+/H+ antiporter.
Explanation:H+ secretion from cells across the luminal membrane is mostly in exchange for Na+ ions, and to a small extent, through a proton ATPase. Secreted H+ react with filtered HC03- to form H2CO3.
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This question is part of the following fields:
- Medicine
- Renal
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Question 11
Correct
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In increasing order of concentration, the main anions in plasma are:
Your Answer: Proteins-, HCO3-, Cl-,
Explanation:Anions are negatively charged ions and include: chloride Cl-, bicarbonate HCO3-, sulphate SO4-2, phosphate HPO4-2, and protein anions. Chloride it the most abundant anion followed by bicarbonate and then protein anions.
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This question is part of the following fields:
- Medicine
- Renal
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Question 12
Correct
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Erythropoietin is synthesized by which cells of the nephron?
Your Answer: Tubular interstitial cells
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Medicine
- Renal
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Question 13
Incorrect
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The position of the kidneys besides the vertebral column retroperitoneally spans levels:
Your Answer: T12 – L2
Correct Answer: T12 – L3
Explanation:The asymmetry within the abdominal cavity, caused by the position of the liver, typically results in the right kidney being slightly lower and smaller than the left, and being placed slightly more to the middle than the left kidney. The left kidney is approximately at the vertebral level T12 to L3, and the right is slightly lower.
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This question is part of the following fields:
- Medicine
- Renal
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Question 14
Correct
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Erythropoietin is synthesized by which cells of the nephron?
Your Answer: Tubular interstitial cells
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Medicine
- Renal
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Question 15
Correct
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Which of the following is a physiological effect of pregnancy on the kidney?
Your Answer: Decreased creatinine
Explanation:A pregnant woman may experience an increase in kidney and ureter size. The glomerular filtration rate (GFR) commonly increases by 50%, returning to normal around 20 weeks postpartum. Plasma sodium does not change because this is offset by the increase in GFR. There is decreased blood urea nitrogen (BUN) and creatinine and potentially glucosuria (due to saturated tubular reabsorption).
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This question is part of the following fields:
- Medicine
- Renal
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Question 16
Correct
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Using the Cockcroft-Gault formula, what will the estimated creatinine clearance be of a 55 year old male who weighs 75kg and has a serum creatinine of 150mg/dL?
Your Answer: 0.59ml/min
Explanation:A commonly used surrogate marker for estimate of creatinine clearance is the Cockcroft-Gault (CG) formula, which in turn estimates GFR in ml/min:CCr = [(140-age) x Mass(kg)]/[72 x serum creatinine (mg/dL)](multiply by 0.85 for women)Therefore CCr = (85 x 75)/(72 x 150) = 0.59
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This question is part of the following fields:
- Medicine
- Renal
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Question 17
Correct
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The Na-K-2Cl co-transporter occurs in which part of the renal tubule?
Your Answer: Apical surface of thick ascending limb
Explanation:The Na-K-Cl cotransporter (NKCC) is a protein that aids in the active transport of sodium, potassium, and chloride into cells. In humans there are two isoforms of this membrane transport protein, NKCC1 and NKCC2. NKCC2 is specifically found in cells of the thick ascending limb of the loop of Henle and the macula densa in nephrons, the basic functional units of the kidney. Within these cells, NKCC2 resides in the apical membrane abutting the nephron’s lumen.
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This question is part of the following fields:
- Medicine
- Renal
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Question 18
Correct
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If UA = concentration of A in urine, V = urine flow per unit time, and PA = arterial plasma level of A, renal clearance of A is equal to?
Your Answer: (UA x V)/PA
Explanation:Renal clearance = [Urine concentration (UA) x Urine flow (V)]/[Plasma concentration (PA)]
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This question is part of the following fields:
- Medicine
- Renal
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Question 19
Correct
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What is the most important determinant of ECF volume?
Your Answer: The amount of sodium in the ECF
Explanation:The volume of the ECF is determined primarily by the total amount of osmotically active solute in the ECF. The composition of the ECF is discussed in Chapter 1. Because Na+ and Cl− are by far the most abundant osmotically active solutes in ECF, and because changes in Cl− are to a great extent secondary to changes in Na+, the amount of Na+ in the ECF is the most important determinant of ECF volume.
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This question is part of the following fields:
- Medicine
- Renal
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Question 20
Correct
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What is the function of the macula densa, located in the wall of the thick ascending limb?
Your Answer: Tubuloglomerular feedback.
Explanation:Macula densa cells sense changes in sodium chloride level, and will trigger an autoregulatory response to increase or decrease reabsorption of ions and water to the blood (as needed) in order to alter blood volume and return blood pressure to normal. Tubuloglomerular feedback is one of several mechanisms the kidney uses to regulate glomerular filtration rate (GFR). It involves the concept of purinergic signalling, in which an increased distal tubular sodium chloride concentration causes a basolateral release of adenosine from the macula densa cells. This initiates a cascade of events that ultimately brings GFR to an appropriate level.
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This question is part of the following fields:
- Medicine
- Renal
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SESSION STATS - PERFORMANCE PER SPECIALTY
