Question 1

Which of the following best describes the effect of antidiuretic hormone (ADH) on the distal convoluted tubule (DCT) and collecting duct?

Accepted Answer

ADH increases the number of aquaporins in the DCT and collecting duct, leading to increased water reabsorption and more concentrated urine.

Question 2

A patient presents with a blood pressure of 90/60 mmHg and decreased glomerular filtration rate (GFR). Which of the following physiological responses would most likely occur to restore GFR?

Accepted Answer

Release of renin from juxtaglomerular cells, activating the renin-angiotensin-aldosterone system (RAAS).

Question 3

Which equation correctly represents the calculation of Net Filtration Pressure (NFP) in the glomerulus?

Accepted Answer

$$NFP = GHP - (GCOP - CHP)$$

Question 4

A patient with diabetes mellitus has a plasma glucose concentration that exceeds the transport maximum (Tm) of the proximal convoluted tubule. What is the most likely consequence?

Accepted Answer

Glucose will appear in the urine, a condition known as glycosuria.

Question 5

Which of the following best explains why the thin descending limb of the nephron loop is critical for the countercurrent multiplier system?

Accepted Answer

It is permeable to water but impermeable to NaCl, allowing water to leave and concentrate the filtrate.

Question 6

A patient is prescribed a loop diuretic. Which part of the nephron is primarily affected, and what is the mechanism of action?

Accepted Answer

Ascending limb of the nephron loop; inhibits Na/K/2Cl symporter, reducing NaCl reabsorption.

Question 7

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

Accepted Answer

Dilation of the afferent arteriole and constriction of the efferent arteriole.

Question 8

Which hormone is released in response to increased blood pressure and causes increased GFR by dilating the afferent arteriole and constricting the efferent arteriole?

Accepted Answer

Atrial natriuretic peptide (ANP)

Question 9

A patient with chronic renal failure is advised to follow a low-protein, low-salt diet. What is the physiological rationale for this recommendation?

Accepted Answer

To reduce the production of nitrogenous wastes and minimize fluid retention, decreasing the workload on the kidneys.

Question 10

Which of the following best describes the role of the vasa recta in the kidney?

Accepted Answer

It maintains the medullary osmotic gradient by countercurrent exchange, allowing for concentrated urine formation.

Question 11

A patient with a urinary tract infection (UTI) is more likely to be female than male. Which anatomical feature best explains this increased risk?

Accepted Answer

Females have a shorter urethra, allowing bacteria easier access to the bladder.

Question 12

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

Accepted Answer

Increases sodium reabsorption and potassium secretion in the distal convoluted tubule and collecting duct.

Question 13

A patient is found to have proteinuria (protein in the urine). Which structure is most likely damaged?

Accepted Answer

The filtration membrane of the glomerulus.

Question 14

Which of the following best describes the composition of normal urine?

Accepted Answer

95% water, 5% solutes such as urea, ions, creatinine, and uric acid.

Question 15

Which of the following scenarios would most likely result in oliguria?

Accepted Answer

Decreased GFR due to severe blood loss and low blood pressure.

Question 16

A patient with high blood pressure is prescribed an ACE inhibitor. What is the primary effect of this medication on the urinary system?

Accepted Answer

It blocks the conversion of angiotensin I to angiotensin II, reducing aldosterone and ADH release, leading to increased urinary output.

Question 17

Which of the following best explains why the renal clearance of inulin is used as a measure of glomerular filtration rate (GFR)?

Accepted Answer

Inulin is freely filtered, not reabsorbed, and not secreted by the nephron.

Question 18

A patient with a kidney stone composed of calcium oxalate is advised to avoid certain foods. Which of the following foods should be limited to reduce the risk of stone formation?

Accepted Answer

Spinach and peanut butter

Question 19

Which of the following best describes the micturition reflex?

Accepted Answer

It is initiated by stretch receptors in the bladder wall when approximately 200 ml of urine accumulates, leading to involuntary contraction of the detrusor muscle and relaxation of the internal urethral sphincter.

Question 20

Which of the following is a function of the juxtaglomerular apparatus (JGA)?

Accepted Answer

Secretion of renin and erythropoietin (EPO) in response to changes in blood pressure.

The Urinary System: Structure, Function, and Regulation

Study Guide - Practice Questions

Study Guide - Flashcards