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 moves substances the body needs from the filtrate back into the blood.

Question 2

Which route of tubular reabsorption involves movement of substances through the cytosol of tubule cells?

Accepted Answer

Transcellular route

Question 3

In the proximal convoluted tubule (PCT), which of the following is TRUE regarding reabsorption?

Accepted Answer

All nutrients such as glucose and amino acids are reabsorbed in the PCT.

Question 4

Which hormone increases water reabsorption in the collecting ducts by promoting the insertion of aquaporins?

Accepted Answer

Antidiuretic hormone (ADH)

Question 5

A patient with diabetes mellitus has high glucose in their urine. Which concept explains why glucose appears in the urine?

Accepted Answer

The transport maximum ($$T_m) $$for glucose reabsorption is exceeded, so excess glucose is excreted.

Question 6

Which of the following correctly matches the nephron loop segment with its permeability?

Accepted Answer

Ascending limb: impermeable to water, permeable to NaCl

Question 7

Which equation is used to calculate renal clearance ($$RC) of a $$substance?

Accepted Answer

$$RC = \frac{UV}{P}$$

Question 8

If a substance has a renal clearance ($$RC) of 0$$, what does this indicate about its handling by the kidney?

Accepted Answer

It is freely filtered, completely reabsorbed, and not secreted.

Question 9

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

Accepted Answer

High levels of antidiuretic hormone (ADH)

Question 10

A patient presents with cloudy urine and a strong ammonia odor. What is the most likely explanation?

Accepted Answer

They may have a urinary tract infection.

Question 11

Which of the following substances is primarily secreted into the filtrate to help regulate blood pH?

Accepted Answer

H+

Question 12

Which of the following is a function of the vasa recta in the kidney?

Accepted Answer

Maintains the medullary osmotic gradient by acting as a countercurrent exchanger.

Question 13

Which of the following would most likely increase the risk of renal calculi (kidney stones)?

Accepted Answer

Chronic bacterial infection and urine retention

Question 14

Which layer of the ureter wall contracts in response to stretch and helps propel urine toward the bladder?

Accepted Answer

Muscularis

Question 15

Which of the following is TRUE regarding the specific gravity of urine?

Accepted Answer

It ranges from 1.001 to 1.035, depending on solute concentration.

Question 16

Which of the following events is controlled by voluntary somatic nervous system activity during urination?

Accepted Answer

Opening of the external urethral sphincter

Question 17

A patient is overhydrated and produces very dilute urine. Which of the following best explains this phenomenon?

Accepted Answer

The collecting duct is impermeable to water due to low ADH levels.

Question 18

Which of the following is a correct statement about the role of aldosterone in the kidney?

Accepted Answer

It promotes synthesis of Na+ and K+ channels and Na+-K+ ATPases in the distal convoluted tubule and collecting duct.

Question 19

Which of the following best describes the effect of osmotic diuretics?

Accepted Answer

They increase urinary output by being substances not reabsorbed, such as high glucose in diabetes.

Urinary System: Tubular Reabsorption and Renal Physiology

Study Guide - Practice Questions