CHBT Renal Physiology and Kidney Disease 2 — Questions and Answers
Question 1: Which two diseases account for the majority of ESRD cases in the United States?
- Diabetes mellitus and hypertension (Correct answer)
- Glomerulonephritis and polycystic kidney disease
- Lupus nephritis and IgA nephropathy
- Obstructive uropathy and pyelonephritis
Correct answer: Diabetes mellitus and hypertension
Diabetic nephropathy and hypertensive nephrosclerosis together cause over 60% of new ESRD cases in the US.
Question 2: What is uremia?
- The syndrome caused by accumulation of uremic toxins when kidneys fail to adequately filter the blood (Correct answer)
- Increased urine output in early kidney disease
- A urinary tract infection caused by urea-splitting bacteria
- Elevated blood urea nitrogen from a high-protein diet alone
Correct answer: The syndrome caused by accumulation of uremic toxins when kidneys fail to adequately filter the blood
Uremia is the clinical syndrome resulting from the retention of nitrogenous and other waste products normally excreted by healthy kidneys.
Question 3: The kidneys play a critical role in vitamin D activation. Which form of vitamin D do the kidneys produce?
- Calcitriol (1,25-dihydroxyvitamin D) (Correct answer)
- Cholecalciferol (vitamin D3)
- Ergocalciferol (vitamin D2)
- 25-hydroxyvitamin D
Correct answer: Calcitriol (1,25-dihydroxyvitamin D)
The kidneys convert 25-hydroxyvitamin D to calcitriol (1,25-dihydroxyvitamin D), the active form that regulates calcium absorption and bone metabolism.
Question 4: Secondary hyperparathyroidism in CKD patients results primarily from:
- Hypocalcemia and hyperphosphatemia triggering excess PTH secretion (Correct answer)
- Parathyroid adenoma formation
- Excess calcium supplementation
- High vitamin D levels
Correct answer: Hypocalcemia and hyperphosphatemia triggering excess PTH secretion
Low calcium and high phosphate levels in CKD chronically stimulate the parathyroid glands, leading to hypertrophy and excess PTH secretion.
Question 5: Which mechanism does the kidney use to regulate systemic blood pressure?
- The renin-angiotensin-aldosterone system (RAAS) (Correct answer)
- Direct neural control of vascular smooth muscle
- Secretion of atrial natriuretic peptide
- Renal prostaglandin inhibition only
Correct answer: The renin-angiotensin-aldosterone system (RAAS)
The kidney releases renin, triggering the RAAS cascade that ultimately increases angiotensin II and aldosterone to raise blood pressure and retain sodium.
Question 6: Residual renal function (RRF) in dialysis patients is important primarily because it:
- Contributes to total solute clearance and fluid removal, improving outcomes (Correct answer)
- Eliminates the need for anticoagulation during treatment
- Prevents access thrombosis
- Reduces the risk of air embolism
Correct answer: Contributes to total solute clearance and fluid removal, improving outcomes
Even small amounts of residual kidney function significantly augment dialysis clearance of uremic toxins and fluid, which is associated with better survival and quality of life.
CHBT Renal Physiology and Kidney Disease 2
Which two diseases account for the majority of ESRD cases in the United States?