Question 1

Which of the following best describes the difference between glomerular filtrate and urine?

Accepted Answer

Glomerular filtrate is mostly protein-free and contains plasma components like nutrients and essential ions, while urine contains metabolic wastes such as creatinine, urea, uric acid, and excess ions but no protein.

Question 2

Which process is responsible for moving water and useful solutes from the renal tubules back into the peritubular capillaries?

Accepted Answer

Tubular reabsorption

Question 3

A patient has a mutation that causes large plasma proteins to pass through the filtration membrane. Which part of the filtration membrane is most likely defective?

Accepted Answer

Fused basement membranes

Question 4

Which equation correctly represents the calculation of net filtration pressure (NFP) in the glomerulus?

Accepted Answer

$$NFP = HP_\mathrm{gc} - (OP_\mathrm{gc} + HP_\mathrm{cs})$$

Question 5

If the glomerular hydrostatic pressure ($$HP_\mathrm{gc}) is 55 mm Hg$$, the blood colloid osmotic pressure ($$OP_\mathrm{gc}) is 30 mm Hg$$, and the capsular hydrostatic pressure ($$HP_\mathrm{cs}) is 15 mm Hg$$, what is the net filtration pressure (NFP)?

Accepted Answer

$$NFP = 55 - (30 + 15) = 10 mm Hg$$

Question 6

Which of the following would most likely cause a decrease in glomerular filtration rate (GFR)?

Accepted Answer

Constriction of the afferent arteriole

Question 7

A patient is experiencing severe blood loss, leading to a drop in systemic blood pressure. Which extrinsic mechanism will the body use to help restore GFR?

Accepted Answer

Release of norepinephrine causing constriction of renal blood vessels

Question 8

Which hormone increases water reabsorption in the kidneys, thereby increasing systemic blood pressure?

Accepted Answer

Antidiuretic hormone (ADH)

Question 9

If the glomerular filtration rate (GFR) is too high, what is the most likely consequence?

Accepted Answer

Insufficient time for reabsorption, leading to loss of useful substances like amino acids and glucose in urine

Question 10

Which intrinsic mechanism allows the kidney to maintain a nearly constant GFR despite changes in systemic blood pressure?

Accepted Answer

Myogenic response of afferent arteriole smooth muscle

Question 11

A drug that blocks sodium reabsorption in the distal convoluted tubule would have what effect on urine output?

Accepted Answer

Increase urine output due to decreased water reabsorption

Question 12

Which of the following best explains why proteins like albumin are not normally found in urine?

Accepted Answer

They are too large to pass through the filtration membrane

Question 13

Which of the following would most likely occur if the afferent arteriole is constricted while the efferent arteriole remains unchanged?

Accepted Answer

Glomerular hydrostatic pressure ($$HP_\mathrm{gc}) $$decreases, decreasing GFR

Question 14

Which cells are responsible for sensing changes in filtrate flow rate and osmolality, thereby regulating GFR via tubuloglomerular feedback?

Accepted Answer

Macula densa cells of the juxtaglomerular apparatus (JGA)

Question 15

A patient is given a drug that increases the permeability of the collecting duct to water. Which hormone is this drug mimicking?

Accepted Answer

Antidiuretic hormone (ADH)

Question 16

Which of the following is a direct effect of aldosterone on the renal tubules?

Accepted Answer

Increased sodium reabsorption

Question 17

During severe dehydration, which hormonal response helps to conserve water and restore blood pressure?

Accepted Answer

Increased ADH and aldosterone secretion

Question 18

Which of the following best describes the role of the myogenic mechanism in renal autoregulation?

Accepted Answer

It causes afferent arteriole smooth muscle to contract or relax in response to changes in systemic blood pressure, maintaining stable GFR.

Question 19

A patient with chronic hypertension is at risk for kidney damage primarily because:

Accepted Answer

High blood pressure increases glomerular hydrostatic pressure, potentially damaging the filtration membrane and impairing GFR regulation.

Question 20

Which of the following scenarios would most likely result in increased GFR?

Accepted Answer

Dilation of the afferent arteriole

The Urinary System: Filtration and Regulation (Chapter 25, Part III)

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