Question 1

Which of the following best describes the process of tubular reabsorption in the nephron?

Accepted Answer

It is a selective transepithelial process that reclaims most tubular contents and returns them to the blood.

Question 2

Which of the following substances is primarily reabsorbed in the proximal convoluted tubule (PCT)?

Accepted Answer

Glucose

Question 3

A patient with uncontrolled diabetes mellitus has glucose present in their urine. This is most likely due to:

Accepted Answer

The transport maximum ($$T_m) $$for glucose being exceeded in the renal tubules.

Question 4

Which hormone increases water reabsorption by causing the insertion of aquaporins into the collecting duct membrane?

Accepted Answer

Antidiuretic hormone (ADH)

Question 5

Which of the following best explains why lipid-soluble drugs can be difficult to eliminate from the body via the kidneys?

Accepted Answer

They are reabsorbed passively along with water down their concentration gradients.

Question 6

Aldosterone acts on which part(s) of the nephron to promote sodium reabsorption?

Accepted Answer

Distal convoluted tubule and collecting duct

Question 7

Which of the following is a function of tubular secretion?

Accepted Answer

Controlling blood pH by secreting $$\mathrm{H}^+ or$$ $$\mathrm{HCO}_3^-$$

Question 8

The countercurrent multiplier mechanism in the nephron loop is responsible for:

Accepted Answer

Establishing the medullary osmotic gradient

Question 9

Which of the following equations correctly represents the calculation for renal clearance ($$C$$)?

Accepted Answer

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

Question 10

A substance has a renal clearance ($$C) of 0 mL/$$min. What does this indicate about the handling of this substance by the kidney?

Accepted Answer

It is completely reabsorbed or not filtered.

Question 11

Which of the following would most likely result in the formation of concentrated urine?

Accepted Answer

Increased secretion of ADH

Question 12

A patient presents with a GFR of 50 mL/min for the past four months. Which condition does this most likely indicate?

Accepted Answer

Chronic renal disease

Question 13

Which of the following is a likely consequence of a large kidney stone lodged in the ureter?

Accepted Answer

Obstruction of urine flow and severe pain radiating from the flank to the abdomen

Question 14

Which of the following best explains why the vasa recta is essential for maintaining the medullary osmotic gradient?

Accepted Answer

It acts as a countercurrent exchanger, preserving the gradient by preventing rapid removal of salt and reabsorbing water.

Question 15

A patient is given a loop diuretic. What is the primary mechanism by which this drug increases urine output?

Accepted Answer

It inhibits the formation of the medullary osmotic gradient in the nephron loop.

Question 16

Which of the following would most likely be found in the urine of a healthy individual?

Accepted Answer

Urea

Question 17

Which of the following best describes the role of the internal urethral sphincter?

Accepted Answer

It is an involuntary smooth muscle that contracts to open at the bladder-urethra junction.

Question 18

A patient with a urine pH of 8.5 and cloudy urine is most likely experiencing which of the following?

Accepted Answer

Urinary tract infection

Question 19

Which of the following events must occur for micturition (urination) to take place?

Accepted Answer

Contraction of the detrusor muscle, opening of the internal urethral sphincter, and relaxation of the external urethral sphincter

Urinary System: Tubular Reabsorption and Renal Physiology 2

Study Guide - Practice Questions