Question 1

Which of the following best describes the main function of the nephron in the kidney?

Accepted Answer

It filters blood, reabsorbs needed substances, and secretes wastes to form urine.

Question 2

A patient with uncontrolled diabetes has glucose detected in their urine. Which renal concept explains this finding?

Accepted Answer

The transport maximum (Tm) for glucose reabsorption has been exceeded.

Question 3

Which pressure is primarily responsible for driving glomerular filtration?

Accepted Answer

Glomerular capillary blood pressure (hydrostatic pressure)

Question 4

If the afferent arteriole constricts, what is the expected effect on glomerular filtration rate (GFR)?

Accepted Answer

GFR will decrease due to reduced blood flow into the glomerulus.

Question 5

Which of the following is NOT a function of the renal system in maintaining homeostasis?

Accepted Answer

Synthesizing insulin for glucose regulation

Question 6

Which part of the nephron is the major site for reabsorption of glucose and amino acids?

Accepted Answer

Proximal convoluted tubule (PCT)

Question 7

A drop in mean arterial pressure (MAP) below 80 mm Hg triggers which control mechanism to maintain GFR?

Accepted Answer

Extrinsic control via sympathetic nervous system and RAAS

Question 8

Which cells in the nephron detect changes in sodium chloride concentration in the tubular fluid and help regulate GFR?

Accepted Answer

Macula densa cells

Question 9

What is the effect of atrial natriuretic peptide (ANP) on sodium reabsorption in the nephron?

Accepted Answer

ANP inhibits sodium reabsorption, leading to increased sodium and water excretion.

Question 10

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

Accepted Answer

$$NFP = (Glomerular\ capillary\ hydrostatic\ pressure) - (Plasma\ colloid\ osmotic\ pressure + Bowman's\ capsule\ hydrostatic\ pressure)$$

Question 11

Which of the following best explains why plasma proteins are not normally found in the filtrate?

Accepted Answer

The filtration membrane is negatively charged and prevents their passage.

Question 12

Which process in the nephron is responsible for selectively adding substances such as potassium and hydrogen ions to the filtrate?

Accepted Answer

Tubular secretion

Question 13

A patient is given a drug that blocks the Na+/K+ ATPase pump in the proximal tubule. What is the most likely effect?

Accepted Answer

Decreased sodium reabsorption and increased sodium in urine

Question 14

Which of the following statements about the loop of Henle is correct?

Accepted Answer

The ascending limb actively pumps out salt but is impermeable to water.

Question 15

Which of the following would most likely increase the glomerular filtration rate (GFR)?

Accepted Answer

Constriction of the efferent arteriole

Question 16

Which mechanism is responsible for maintaining nearly constant GFR when mean arterial pressure is between 80 and 180 mm Hg?

Accepted Answer

Renal autoregulation (intrinsic control)

Question 17

Which of the following is a correct sequence of urine formation in the nephron?

Accepted Answer

Filtration → Reabsorption → Secretion

Question 18

Which hormone increases water reabsorption in the collecting duct by increasing the number of aquaporins?

Accepted Answer

Antidiuretic hormone (ADH)

Question 19

Which of the following is true regarding juxtamedullary nephrons?

Accepted Answer

They have longer loops of Henle and are crucial for producing concentrated urine.

Question 20

A patient with high plasma potassium levels is at risk for which renal process malfunction?

Accepted Answer

Impaired tubular secretion in the distal nephron

Chapter 25: The Urinary System – Structure, Function, and Regulation

Study Guide - Practice Questions