Question 1

Which of the following best describes the primary function of the nephron in the urinary system?

Accepted Answer

To filter blood, reclaim needed substances, and excrete wastes as urine

Question 2

A patient presents with glucose in their urine. Which concept explains why this occurs in diabetes mellitus?

Accepted Answer

The transport maximum ($T_m$) for glucose is exceeded, so excess glucose is not reabsorbed

Question 3

Which pressure is the main controllable factor in determining glomerular filtration rate (GFR)?

Accepted Answer

Hydrostatic pressure in the glomerular capillaries ($HP_{gc}$)

Question 4

A patient is severely dehydrated. Which hormone will be released to increase water reabsorption in the collecting ducts?

Accepted Answer

Antidiuretic hormone (ADH)

Question 5

Which of the following best explains the countercurrent multiplier mechanism in the nephron loop?

Accepted Answer

It creates an osmotic gradient in the medulla by pumping NaCl out of the ascending limb

Question 6

Which of the following substances is primarily secreted by the kidneys to regulate blood pressure?

Accepted Answer

Renin

Question 7

A patient is given a drug that inhibits sodium reabsorption in the ascending limb of the nephron loop. What is the expected effect?

Accepted Answer

Increased urine output due to disruption of the medullary osmotic gradient

Question 8

Which equation correctly calculates renal clearance ($C$) for a substance?

Accepted Answer

$C = \frac{U 	imes V}{P}$

Question 9

Which of the following is TRUE regarding the permeability of the nephron loop?

Accepted Answer

The ascending limb is impermeable to water but actively transports NaCl

Question 10

A patient with chronic renal disease has a GFR of 40 mL/min for over 3 months. Which of the following is a likely consequence?

Accepted Answer

Accumulation of nitrogenous wastes in the blood (azotemia)

Question 11

Which of the following is a function of tubular secretion in the nephron?

Accepted Answer

Disposing of substances bound to plasma proteins

Question 12

Which hormone acts on the distal convoluted tubule (DCT) to increase calcium reabsorption?

Accepted Answer

Parathyroid hormone (PTH)

Question 13

Which of the following would most likely result in the formation of kidney stones?

Accepted Answer

Frequent urinary tract infections and high urine calcium concentration

Question 14

Which of the following is TRUE about the juxtaglomerular complex (JGC)?

Accepted Answer

It regulates filtrate formation and blood pressure via modified cells in the distal nephron and arterioles

Question 15

Which of the following is a direct effect of aldosterone on the nephron?

Accepted Answer

Increases sodium reabsorption and potassium secretion in the DCT and collecting duct

Question 16

Which of the following would most likely cause overflow incontinence?

Accepted Answer

Overfilling of the bladder due to obstruction or nerve damage

Question 17

Which of the following is the correct sequence of urine flow through the nephron and urinary tract?

Accepted Answer

Glomerulus → Proximal tubule → Nephron loop → Distal tubule → Collecting duct → Minor calyx → Ureter → Bladder → Urethra

Question 18

Which of the following is a normal characteristic of urine?

Accepted Answer

Slightly acidic pH (around 6)

Question 19

A patient is given inulin to measure GFR. If $U = 125$ mg/mL, $V = 1$ mL/min, and $P = 1$ mg/mL, what is the GFR?

Accepted Answer

$GFR = \frac{125 	imes 1}{1} = 125$ mL/min

Question 20

Which of the following mechanisms allows the kidneys to produce concentrated urine during dehydration?

Accepted Answer

Increased ADH secretion and utilization of the medullary osmotic gradient

Urinary System: Structure, Function, and Physiology

Study Guide - Practice Questions