Questions: Excretory System: characteristics, kidneys, and diseases
Multiple-Choice Questions: Excretory System
1. What is the main function of the excretory system?
A) Circulation of blood
B) Regulation of hormones
C) Removal of metabolic wastes
D) Absorption of nutrients
E) Production of enzymes
2. Which organ is primarily responsible for filtering blood to form urine?
A) Liver
B) Bladder
C) Kidney
D) Pancreas
E) Spleen
3. What is the structural and functional unit of the kidney?
A) Alveolus
B) Nephron
C) Glomerulus
D) Ureter
E) Loop of Henle
4. Urine is transported from the kidneys to the bladder through:
A) Urethra
B) Loop of Henle
C) Nephrons
D) Ureters
E) Renal vein
5. Which part of the nephron is responsible for the filtration of blood?
A) Loop of Henle
B) Proximal tubule
C) Glomerulus
D) Distal tubule
E) Collecting duct
6. The kidney helps regulate all of the following EXCEPT:
A) Blood pressure
B) pH level
C) Oxygen production
D) Water balance
E) Electrolyte concentration
7. Which hormone controls the reabsorption of water in the kidneys?
A) Insulin
B) Adrenaline
C) Antidiuretic hormone (ADH)
D) Glucagon
E) Estrogen
8. What is the name of the disease characterized by the inability of the kidneys to filter waste properly?
A) Nephritis
B) Diabetes
C) Renal failure
D) Gallstones
E) Hepatitis
9. What is the purpose of dialysis?
A) Strengthen kidney function
B) Remove the kidney stones
C) Artificially filter blood when kidneys fail
D) Increase urine production
E) Reduce blood glucose levels
10. Which of these is NOT part of the human excretory system?
A) Kidneys
B) Ureters
C) Lungs
D) Bladder
E) Large intestine
11. What waste product is primarily excreted in the urine?
A) Glucose
B) Urea
C) Oxygen
D) Bile
E) Hemoglobin
12. Which organ also plays a role in excretion by removing carbon dioxide?
A) Liver
B) Skin
C) Pancreas
D) Lungs
E) Small intestine
13. The bladder is a:
A) Muscular sac that stores bile
B) Gland that produces hormones
C) Tube connecting kidney to urethra
D) Muscular sac that stores urine
E) Valve that filters blood
14. Which condition involves crystals forming in the kidneys and causing pain?
A) Cystitis
B) Kidney stones
C) Uremia
D) Nephronitis
E) Urinary retention
15. Which blood vessel carries blood away from the kidney?
A) Renal artery
B) Renal vein
C) Aorta
D) Inferior vena cava
E) Pulmonary vein
16. What structure in the nephron reabsorbs most of the nutrients and water?
A) Glomerulus
B) Proximal convoluted tubule
C) Bowman's capsule
D) Collecting duct
E) Ureter
17. Which of the following can be a symptom of kidney failure?
A) Frequent bowel movements
B) Difficulty breathing
C) Fatigue and fluid retention
D) Blurred vision
E) Skin rash
18. What is the Bowman's capsule?
A) A capillary network
B) A tube that drains urine
C) A sac that collects filtrate from the glomerulus
D) A hormone-secreting gland
E) A part of the urethra
19. Which of these is NOT filtered out by the kidneys under normal conditions?
A) Urea
B) Glucose
C) Salts
D) Water
E) Red blood cells
20. Which process allows substances to be selectively reabsorbed into the blood?
A) Filtration
B) Diffusion
C) Secretion
D) Reabsorption
E) Evaporation
21. Which part of the nephron creates a concentration gradient in the medulla?
A) Glomerulus
B) Distal tubule
C) Proximal tubule
D) Loop of Henle
E) Collecting duct
22. Uremia is a condition caused by:
A) Excess water in blood
B) Lack of hemoglobin
C) High levels of urea in the blood
D) Blocked bile ducts
E) Low oxygen levels
23. Which test is commonly used to assess kidney function?
A) Blood glucose test
B) Blood pressure test
C) Urinalysis
D) EEG
E) X-ray
24. What excretory function is performed by the skin?
A) Producing hormones
B) Filtering blood
C) Secreting sweat
D) Producing bile
E) Digesting nutrients
25. What happens to urine once it leaves the kidneys?
A) It's absorbed into the blood
B) It's stored in the urethra
C) It's reabsorbed by the liver
D) It's transported to the bladder
E) It's expelled immediately
26. What is the urethra?
A) The duct that delivers bile
B) The vessel that returns blood to the kidneys
C) The tube that carries urine from bladder to the outside
D) The capillary network in the glomerulus
E) The muscular layer of the kidney
27. What triggers the sensation of needing to urinate?
A) Contraction of the kidneys
B) Dehydration
C) Stretching of the bladder wall
D) Hormone secretion
E) Increased heart rate
28. Polycystic kidney disease is:
A) A viral infection
B) A genetic disorder involving cysts in the kidney
C) A result of bacterial contamination
D) Due to lack of salt
E) A type of cancer
29. Which of the following can help prevent kidney disease?
A) High sugar diet
B) Excessive alcohol intake
C) Drinking plenty of water
D) Avoiding fruits
E) Reducing physical activity
30. Which of the following is a diuretic?
A) Water
B) Caffeine
C) Sodium
D) Protein
E) Iron
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Answer Key with Explanations
1. C – The excretory system removes waste products from the body.
2. C – The kidneys filter blood to produce urine.
3. B – The nephron is the functional unit of the kidney.
4. D – Ureters transport urine to the bladder.
5. C – The glomerulus filters blood in the nephron.
6. C – Kidneys don’t produce oxygen.
7. C – ADH increases water reabsorption in kidneys.
8. C – Renal failure is the loss of kidney function.
9. C – Dialysis removes waste when kidneys fail.
10. E – The large intestine is not part of the excretory system.
11. B – Urea is a waste product excreted in urine.
12. D – Lungs excrete carbon dioxide.
13. D – The bladder stores urine.
14. B – Kidney stones are crystal formations that block urine flow.
15. B – The renal vein carries filtered blood away from the kidney.
16. B – The proximal tubule reabsorbs most nutrients and water.
17. C – Kidney failure can cause fluid buildup and fatigue.
18. C – Bowman's capsule collects filtrate from the glomerulus.
19. E – Blood cells are normally too large to pass through the filter.
20. D – Reabsorption allows certain substances to return to the blood.
21. D – The Loop of Henle creates a concentration gradient.
22. C – Uremia is caused by excess urea in the blood.
23. C – Urinalysis helps evaluate kidney health.
24. C – Skin helps excrete waste via sweat.
25. D – Urine flows to the bladder after leaving the kidneys.
26. C – The urethra carries urine out of the body.
27. C – Stretch receptors in the bladder signal the need to urinate.
28. B – Polycystic kidney disease is a hereditary condition.
29. C – Staying hydrated helps prevent kidney damage.
30. B – Caffeine acts as a diuretic, increasing urine output.
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