Q: Which equation correctly represents the action of the Na+/K+-ATPase in the proximal tubule?

$$3\mathrm{Na}^+_{\text{in}} + 2\mathrm{K}^+_{\text{out}} + \mathrm{ATP} \rightarrow 3\mathrm{Na}^+_{\text{out}} + 2\mathrm{K}^+_{\text{in}} + \mathrm{ADP} + P_i$$

Question 1

Which of the following best describes the main function of the proximal convoluted tubule in the nephron?

Accepted Answer

Reabsorption of water, salts, sugars, and amino acids

Question 2

The reabsorption of D-glucose in the proximal tubule is primarily driven by which transport mechanism?

Accepted Answer

Secondary active transport via SGLT1 coupled to Na+

Question 3

Which equation correctly represents the action of the Na+/K+-ATPase in the proximal tubule?

Accepted Answer

$$3\mathrm{Na}^+_{	ext{in}} + 2\mathrm{K}^+_{	ext{out}} + \mathrm{ATP} ightarrow 3\mathrm{Na}^+_{	ext{out}} + 2\mathrm{K}^+_{	ext{in}} + \mathrm{ADP} + P_i$$

Question 4

A patient with a genetic defect in aquaporin-1 channels would most likely have impaired water reabsorption in which part of the nephron?

Accepted Answer

Thin descending limb of the loop of Henle

Question 5

Which histological feature is most characteristic of the proximal convoluted tubule under the microscope?

Accepted Answer

Tall columnar cells with prominent brush border

Question 6

Aldosterone increases sodium reabsorption in the collecting duct by upregulating which proteins?

Accepted Answer

ENaC and Na+/K+-ATPase

Question 7

Which of the following best explains why small hydrophobic molecules are poorly filtered by the renal corpuscle?

Accepted Answer

They bind to plasma proteins, preventing filtration

Question 8

The juxtaglomerular apparatus regulates blood pressure by releasing renin in response to which physiological change?

Accepted Answer

Decrease in arterial blood pressure

Question 9

Which sequence correctly describes the Renin-Angiotensin-Aldosterone System (RAAS) activation?

Accepted Answer

Renin release → Angiotensin II formation → Aldosterone secretion → Increased Na+ reabsorption

Question 10

Which of the following is the correct formula for the acid-base reaction occurring in intercalated cells during acidosis?

Accepted Answer

$$\mathrm{H}^+ + \mathrm{HCO}_3^- \rightarrow \mathrm{H}_2CO_3 \rightarrow \mathrm{CO}_2 + \mathrm{H}_2O$$

Question 11

Which part of the nephron is primarily responsible for the final adjustment of urine osmolality?

Accepted Answer

Collecting duct

Question 12

A patient with diabetes insipidus is unable to concentrate urine due to a lack of which hormone?

Accepted Answer

Antidiuretic hormone (ADH)

Question 13

Which type of epithelium lines the urinary tract collecting system, including the renal pelvis, ureter, and bladder?

Accepted Answer

Transitional epithelium (urothelium)

Question 14

Which of the following correctly matches the nephron segment with its permeability to water and salts?

Accepted Answer

Thin descending limb: permeable to water, impermeable to salts

Question 15

Which of the following is NOT a function of the juxtaglomerular apparatus?

Accepted Answer

Regulation of acid-base balance

Question 16

During alkalosis, which process occurs in the intercalated cells of the collecting duct?

Accepted Answer

Bicarbonate (HCO$$_3^-) is $$released into the urine

Question 17

Which anatomical structure is responsible for the voluntary control of urination?

Accepted Answer

External urethral sphincter (skeletal muscle)

Question 18

Which of the following kidney malformations is characterized by fusion of the lower poles of the kidneys?

Accepted Answer

Horseshoe kidney

Question 19

Which step in urine production is most affected by the presence of large plasma proteins in the blood?

Accepted Answer

Filtration in the renal corpuscle

Question 20

Which of the following best explains the effect of ADH on the collecting duct?

Accepted Answer

Stimulates expression of aquaporin-2 and increases water reabsorption

Renal Histology and Physiology: Tubular Reabsorption and Urinary Tract Structure

Study Guide - Practice Questions

Study Guide - Flashcards