Renal

In which region of the nephron does the fractional reabsorption of water vary the most in response to variation in the state of hydration? a. the collecting duct b. the distal convoluted tubule c. the loop of Henle d. the proximal convoluted tubule e. the glomerulus

A

Water and NaCl reabsorbed from the loop of Henle directly re-enter what blood vessels? a. vasa recta b. collecting ducts c. efferent arterioles d. afferent arterioles e. cortical peritubular capillaries

A

Which correctly describes the composition of the glomerular filtrate? a. It is highly similar to plasma, except it does not contain plasma proteins. b. It is identical to blood plasma, except it lacks red blood cells. c. It is identical to urine, but has a much larger flow rate. d. It is identical to urine, but has a much smaller flow rate. e. It is highly similar to plasma, except it contains plasma proteins.

A

In what segment of the nephron is the greatest fraction of filtered water reabsorbed? a. the descending limb of the loop of Henle b. the proximal tubule c. the ascending limb of the loop of Henle d. the distal convoluted tubule e. the collecting ducts

B

Which of the following statements about renal control of blood acid/base balance is TRUE? Select one: a. H+ that binds to filtered bicarbonate in the tubular fluid is excreted in the urine. b. Increased metabolism of glutamine by renal tubular cells increases the plasma bicarbonate concentration. c. Excretion in the urine of hydrogen bound to phosphate buffers decreases plasma bicarbonate concentration. d. The kidneys compensate for a metabolic alkalosis by increasing CO2 production. e. When hypoventilation occurs at the lungs, the kidneys compensate by reducing glutamine metabolism.

B

The amount of a substance that is excreted in the urine is equal to the amount that is ________ plus the amount that is ________ minus the amount that is ________. a. reabsorbed; secreted; filtered b. filtered; reabsorbed; secreted c. filtered; secreted; reabsorbed d. reabsorbed; filtered; secreted e. secreted; reabsorbed; filtered

C

What change in renal regulation of H+ would help compensate for a metabolic acidosis? Select one: a. a decrease in the amount of H+ secreted in the proximal tubule b. an increase in the urinary pH c. an increase in the production of new plasma HCO3- d. a decrease in the tubular production of ammonia e. a decrease in the filtered load of H+

C

What is the rate-limiting (regulated) step for stimulating the secretion of aldosterone? Select one: a. secretion of angiotensinogen by the liver b. secretion of ACTH by the anterior pituitary c. conversion of angiotensinogen to angiotensin I in the blood d. secretion of angiotensin II by the kidney e. conversion of angiotensin I to angiotensin II in the blood

C

Which correctly describes a basic renal process? a. Substances are secreted from the tubule into the peritubular capillaries. b. Fluid is filtered from Bowman's capsule into the glomerulus. c. Fluid moves by bulk flow from glomerular capillaries into Bowman's space. d. Substances are reabsorbed from the capillaries into the tubular lumen. e. Substances are actively secreted from glomerular capillaries into Bowman's capsule.

C

Which correctly describes renin? Select one: a. Its secretion is enhanced by high levels of Na+ in the macula densa. b. Its secretion is stimulated by elevated blood pressure in the renal afferent arterioles. c. It is secreted by juxtaglomerular cells in renal afferent arterioles. d. It is secreted by the liver in response to low blood pressure. e. It acts on the adrenal cortex to stimulate aldosterone secretion.

C

Which equation is equal to the net glomerular filtration pressure? a. = osmotic pressure due to protein in plasma - hydrostatic pressure in glomerular capillaries - hydrostatic pressure in Bowman's capsule b. = hydrostatic pressure in glomerular capillaries + hydrostatic pressure in Bowman's capsule + osmotic pressure due to protein in plasma c. = hydrostatic pressure in glomerular capillaries - hydrostatic pressure in Bowman's capsule - osmotic force due to proteins in plasma d. = hydrostatic pressure in glomerular capillaries + hydrostatic pressure in Bowman's capsule - osmotic pressure due to protein in plasma e. = hydrostatic pressure in glomerular capillaries - hydrostatic pressure in Bowman's capsule - osmotic pressure due to protein in Bowman's capsule

C

Which is NOT a transport mechanism typically seen in renal tubular epithelial cells? a. transport proteins that move glucose by facilitated diffusion from inside of proximal tubule cells into the renal interstitial fluid b. ion channels that allow Na+ to move by diffusion from the lumen of the proximal tubule into epithelial cells c. Na+-K+ ATPase pumps in the luminal membrane of proximal tubule epithelial cells that move Na+ from inside the cell into the tubule and K+ from the tubule lumen into the cell d. cotransport proteins in the luminal membrane of the proximal tubule that move Na+ and glucose from the proximal tubule into epithelial cells e. countertransport proteins that move Na+ into proximal tubule epithelial cells while moving H+ from the cells into the lumen

C

Which is NOT true about the countercurrent multiplier system of the kidney? a. The ascending loop of Henle is not permeable to water. b. It creates a hyperosmolar medullary interstitium that allows the kidneys to form hypertonic urine. c. The fraction of filtered NaCl reabsorbed from the ascending limb equals the fraction of filtered water reabsorbed from the descending limb. d. The descending loop of Henle is permeable to water. e. There is active transport of sodium and chloride out of the ascending limb of the loop of Henle.

C

Which is TRUE regarding renal tubular reabsorption? a. Reabsorption of Na+ only occurs from nephron regions that come after the descending limb of the loop of Henle. b. Toxic substances are removed from the body by reabsorption from peritubular capillaries into the proxmial tubule. c. Reabsorption of glucose saturates at a maximum transport rate. d. Reabsorption of Na+ from the proximal tubule occurs as a result of water reabsorption. e. Urea reabsorption cannot occur at any point along the nephron.

C

Which of the following statements about renal control of blood acid/base balance is TRUE? Select one: a. When hypoventilation occurs at the lungs, the kidneys compensate by reducing glutamine metabolism. b. H+ that binds to filtered bicarbonate in the tubular fluid is excreted in the urine. c. Increased metabolism of glutamine by renal tubular cells increases the plasma bicarbonate concentration. d. Excretion in the urine of hydrogen bound to phosphate buffers decreases plasma bicarbonate concentration. e. The kidneys compensate for a metabolic alkalosis by increasing CO2 production.

C

In the condition diabetes mellitus, why does glucose appear in the urine? a. Without the hormone insulin, glucose cannot enter proximal tubule epithelial cells. b. Without insulin, the glomerular filtration barrier becomes extremely leaky to glucose, which is not normally fiterable. c. The plasma concentration of glucose becomes so high that it diffuses from peritubular capillaries into the proximal tubule, down its concentration gradient. d. The filtered load of glucose becomes greater than the tubular maximum for its reabsorption. e. The rate of tubular secretion of glucose becomes greater than the sum of glucose filtration and reabsorption.

D

What region of the nephron reabsorbs about two-thirds of filtered Na+ and Cl-? a. ascending loop of Henle b. glomerulus c. distal convoluted tubule d. proximal convoluted tubule e. collecting duct

D

Which of the following is least likely to be filtered into Bowman's capsule in a normal, healthy person? a. glucose b. bicarbonate ion c. sodium d. plasma protein e. urea

D

Which of the following would be most likely to increase GFR? Select one: a. an increase in the concentration of plasma proteins b. sympathetic stimulation of afferent arteriolar smooth muscle c. an increased secretion of renin d. constricting efferent arterioles e. a decrease in plasma volume

D

All of the following substances are present in proximal tubular fluid in the kidney, but which one is NOT normally present in urine? a. HPO4- b. K+ c. H+ d. Ca2+ e. glucose

E

Which is TRUE about the hormone vasopressin (also known as antidiuretic hormone, ADH)? a. It stimulates the excretion of K+ in the urine. b. It promotes the excretion of more water in the urine. c. It's main function is to trigger the secretion of aldosterone. d. It is a peptide hormone released from the adrenal gland. e. It triggers insertion of aquaporins into the apical membranes of collecting duct cells.

E

Which of the following most accurately describes the actions of aldosterone? Select one: a. Aldosterone increases Na+ reabsorption and K+ secretion in the proximal tubule. b. Aldosterone decreases Na+ reabsorption and K+ secretion in the cortical collecting ducts. c. Aldosterone increases Na+ secretion and K+ reabsorption in the cortical collecting ducts. d. Aldosterone increases Na+ secretion and K+ reabsorption in the proximal tubule. e. Aldosterone increases Na+ reabsorption and K+ secretion in the cortical collecting ducts.

E

Which of the following most accurately describes the renal transport of Na+? a. Na+ is actively transported across the luminal membrane of proximal tubule cells in exchange for K+, by Na+/K+ ATPase pumps. b. Na+ is actively secreted into the nephron lumen by cells in the cortical collecting ducts. c. Na+ is actively transported in all segments of the tubule. d. Most of the Na+ transport occurs in the distal convoluted tubule and collecting ducts. e. Primary active transport of Na+ allows for secondary active transport of glucose and H+ in the proximal tubule.

E

Which of the following organs is the main site of aldosterone secretion? Select one: a. systemic and pulmonary blood vessels b. liver c. the atria of the heart d. kidneys e. adrenal glands

E

Which of the following statements concerning the process of glomerular filtration is correct? a. All of the plasma that enters the glomerular capillaries is filtered. b. The hydrostatic pressure in glomerular capillaries opposes filtration. c. The osmotic force due to plasma proteins favors filtration. d. The glomerular filtration rate is limited by a transport maximum. e. The hydrostatic pressure in Bowman's space opposes filtration.

E

A consequence of lack of vasopressin is excretion of sugar in the urine, which occurs in the condition diabetes mellitus. Select one: True False

False

Only substances that are filtered by the kidneys can be excreted by them. Select one: True False

False

The walls of the ascending limb of the loop of Henle are freely permeable to water. Select one: True False

False

Water, sodium, and glucose all undergo tubular reabsorption, but urea does not. Select one: True False

False

he distal convoluted tubules drain directly into the renal pelvis, which in turn drains into the ureter, a tube that carries urine to the bladder. Select one: True False

False

A stimulus for increased aldosterone secretion is increased plasma levels of K+. Select one: True False

True

In healthy individuals, the amount of glucose present in urine will be virtually zero because the amount of glucose reabsorption from the filtrate back into the blood prevents excretion. Select one: True False

True

The anatomic arrangement of juxtamedullary nephrons in the kidneys is such that the glomerulus, proximal tubule, and distal convoluted tubule are in the renal cortex, while the loop of Henle and collecting ducts lie mainly in the renal medulla. Select one: True False

True

The countercurrent mechanism of the kidney enables the formation of hypertonic urine. Select one: True False

True

Unlike the renal cortical interstitial fluid, the interstitial fluid of the medulla is hyperosmotic. Select one: True False

True

Water absorption from the proximal tubule is mainly driven by the active reabsorption of Na+. Select one: True False

True