CSR Renal Physiology & Pathophysiology

Question 1

What is the primary function of the glomerulus in the nephron?

Accepted Answer

Filters blood to form primary urine

Answer

The glomerulus is a network of tiny blood vessels (capillaries) located at the beginning of a nephron in the kidney. Its primary function is ultrafiltration, where blood plasma, excluding large proteins and blood cells, is filtered from the capillaries into Bowman's capsule. This process forms the initial filtrate, or primary urine, which then proceeds through the rest of the nephron for further processing.

Question 2

Which hormone is most directly involved in sodium reabsorption in the distal nephron?

Accepted Answer

Aldosterone

Answer

Aldosterone is a mineralocorticoid hormone produced by the adrenal cortex that acts directly on the principal cells of the distal convoluted tubule and collecting duct in the kidney. Its primary function is to increase sodium reabsorption and potassium excretion. This action helps regulate blood pressure and maintain fluid balance within the body.

Question 3

What is the role of the loop of Henle in urine concentration?

Accepted Answer

Generates a medullary concentration gradient

Answer

The loop of Henle is crucial for concentrating urine by establishing a medullary osmotic gradient through the countercurrent multiplier system. The descending limb is permeable to water, while the ascending limb actively transports solutes like sodium and chloride out of the tubule. This creates a hyperosmotic environment in the renal medulla, which is then utilized by the collecting ducts to reabsorb water, leading to concentrated urine.

Question 4

Which of the following is a common early symptom of chronic kidney disease (CKD)?

Accepted Answer

Fatigue

Answer

Fatigue is a common early symptom of chronic kidney disease (CKD) due to several contributing factors. As kidney function declines, waste products accumulate, leading to uremia, and patients often develop anemia from decreased erythropoietin production. These combined effects result in a general feeling of tiredness, weakness, and reduced energy levels.

Question 5

How does metabolic acidosis commonly develop in CKD patients?

Accepted Answer

From reduced acid excretion and bicarbonate reabsorption

Answer

Metabolic acidosis commonly develops in CKD patients because their impaired kidneys are less able to excrete hydrogen ions (acid) and regenerate or reabsorb bicarbonate. As kidney function declines, the body's buffering capacity is overwhelmed, leading to an accumulation of acid. This imbalance results in a decrease in blood pH, which is characteristic of metabolic acidosis.

(CSR) Board Certified Specialist in Renal Nutrition Practice Test

(CSR) Board Certified Specialist in Renal Nutrition Practice Test

CSR Renal Physiology & Pathophysiology