1. What is the primary function of the kidneys in the human body?
a) Blood circulation
b) Regulation of body temperature
c) Filtration of blood and regulation of homeostasis
d) Protein synthesis
Answer: c) Filtration of blood and regulation of homeostasis
2. The functional unit of the kidney is known as the:
a) Neuron
b) Nephron
c) Glomerulus
d) Alveolus
Answer: b) Nephron
3. Which part of the nephron is responsible for the filtration of blood?
a) Proximal convoluted tubule
b) Glomerulus
c) Distal convoluted tubule
d) Loop of Henle
Answer: b) Glomerulus
4. Which substance is primarily reabsorbed in the proximal convoluted tubule of the nephron?
a) Sodium ions
b) Water
c) Glucose
d) All of the above
Answer: d) All of the above
5. Which of the following is NOT a waste product excreted by the kidneys?
a) Urea
b) Ammonia
c) Oxygen
d) Uric acid
Answer: c) Oxygen
6. The kidneys maintain homeostasis by regulating the balance of:
a) Water, salts, and blood pressure
b) Glucose and amino acids
c) Calcium and magnesium ions
d) All of the above
Answer: a) Water, salts, and blood pressure
7. The process by which substances are selectively moved from the blood into the nephron is known as:
a) Filtration
b) Secretion
c) Reabsorption
d) Excretion
Answer: a) Filtration
8. The loop of Henle is primarily responsible for:
a) Reabsorbing glucose
b) Concentrating urine
c) Filtration of plasma
d) Secretion of waste
Answer: b) Concentrating urine
9. The hormone aldosterone regulates the balance of which substance in the kidneys?
a) Water
b) Sodium
c) Potassium
d) Urea
Answer: b) Sodium
10. The hormone antidiuretic hormone (ADH) primarily regulates the reabsorption of:
a) Glucose
b) Water
c) Sodium
d) Urea
Answer: b) Water
11. What is the primary function of the collecting duct in the kidney?
a) Filtration of blood
b) Reabsorption of glucose
c) Reabsorption of water and concentration of urine
d) Secretion of nitrogenous wastes
Answer: c) Reabsorption of water and concentration of urine
12. The kidneys help regulate blood pressure through the renin-angiotensin-aldosterone system by controlling the reabsorption of:
a) Sodium and water
b) Calcium
c) Potassium
d) Glucose
Answer: a) Sodium and water
13. Which of the following is a key component of the filtration barrier in the kidneys?
a) Podocytes
b) Erythrocytes
c) Thrombocytes
d) Lymphocytes
Answer: a) Podocytes
14. Which of the following conditions is related to kidney malfunction?
a) Hypertension
b) Hyperglycemia
c) Hyperthyroidism
d) Hypoxia
Answer: a) Hypertension
15. The presence of protein in urine is often indicative of:
a) Glomerular damage
b) Excessive water intake
c) Diabetes insipidus
d) Kidney stones
Answer: a) Glomerular damage
16. The kidneys contribute to acid-base balance by regulating the secretion of:
a) Bicarbonate ions
b) Hydrogen ions
c) Both a and b
d) Potassium ions
Answer: c) Both a and b
17. The blood entering the kidneys for filtration is supplied by the:
a) Renal vein
b) Renal artery
c) Aorta
d) Inferior vena cava
Answer: b) Renal artery
18. Which of the following is a function of the renal corpuscle?
a) Secretion of hormones
b) Filtration of blood
c) Reabsorption of water
d) Reabsorption of glucose
Answer: b) Filtration of blood
19. In which part of the nephron does the majority of reabsorption occur?
a) Distal convoluted tubule
b) Proximal convoluted tubule
c) Loop of Henle
d) Collecting duct
Answer: b) Proximal convoluted tubule
20. Urine formation begins in the:
a) Collecting duct
b) Loop of Henle
c) Glomerulus
d) Proximal convoluted tubule
Answer: c) Glomerulus
21. Which of the following ions are primarily reabsorbed in the distal convoluted tubule?
a) Sodium and calcium
b) Potassium and sodium
c) Calcium and magnesium
d) Bicarbonate and chloride
Answer: a) Sodium and calcium
22. The kidneys help to regulate the concentration of which of the following in the blood?
a) Oxygen
b) Glucose
c) Water and electrolytes
d) Iron
Answer: c) Water and electrolytes
23. Which of the following structures is responsible for the transport of urine from the kidneys to the urinary bladder?
a) Urethra
b) Ureter
c) Renal pelvis
d) Renal tubule
Answer: b) Ureter
24. What is the term for the condition when the kidneys cannot filter waste effectively?
a) Renal failure
b) Nephritis
c) Uremia
d) Glomerulonephritis
Answer: a) Renal failure
25. In which structure of the nephron is the filtrate modified by the reabsorption and secretion of substances?
a) Renal capsule
b) Renal tubule
c) Glomerulus
d) Ureter
Answer: b) Renal tubule
26. Which of the following is a role of the kidneys in maintaining homeostasis?
a) Regulating blood glucose levels
b) Filtering waste products from the blood
c) Producing insulin
d) Regulating body temperature
Answer: b) Filtering waste products from the blood
27. What is the final product of kidney filtration and reabsorption?
a) Urine
b) Sweat
c) Plasma
d) Blood
Answer: a) Urine
28. The kidneys are responsible for maintaining the balance of which of the following electrolytes?
a) Potassium
b) Sodium
c) Calcium
d) All of the above
Answer: d) All of the above
29. Which of the following hormones produced by the kidneys regulates red blood cell production?
a) Renin
b) Erythropoietin
c) Aldosterone
d) Insulin
Answer: b) Erythropoietin
30. The condition where the kidneys fail to remove waste from the blood is called:
a) Kidney stones
b) Uremia
c) Glomerulonephritis
d) Renal failure
Answer: b) Uremia
These MCQs cover the key concepts of the excretory system and the role of kidneys in maintaining homeostasis, providing a comprehensive overview of the subject.
