1. What is the primary function of the excretory system in humans?
a. Digestion
b. Respiration
c. Waste elimination
d. Blood circulation
Answer: c. Waste elimination
2. Which of the following is a nitrogenous waste product commonly excreted by mammals?
a. Carbon dioxide
b. Urea
c. Glucose
d. Oxygen
Answer: b. Urea
3. Where does the majority of nutrient and water reabsorption occur in the human excretory system?
a. Renal pelvis
b. Glomerulus
c. Loop of Henle
d. Collecting duct
Answer: c. Loop of Henle
4. Which organ is responsible for filtering blood and forming urine in the human body?
a. Liver
b. Kidney
c. Lungs
d. Heart
Answer: b. Kidney
5. What is the functional unit of the kidney responsible for filtration and urine formation?
a. Nephron
b. Ureter
c. Bladder
d. Urethra
Answer: a. Nephron
6. Which hormone regulates water reabsorption in the kidneys?
a. Insulin
b. Thyroxine
c. Antidiuretic hormone (ADH)
d. Estrogen
Answer: c. Antidiuretic hormone (ADH)
7. Which of the following is not a component of urine?
a. Urea
b. Glucose
c. Creatinine
d. Sodium
Answer: b. Glucose
8. What is the primary role of the urethra in the excretory system?
a. Filtration
b. Storage of urine
c. Transportation of urine out of the body
d. Reabsorption
Answer: c. Transportation of urine out of the body
9. Which condition is characterized by the inflammation of the renal pelvis and kidneys, often caused by bacterial infection?
a. Nephritis
b. Nephrosis
c. Uremia
d. Cystitis
Answer: a. Nephritis
10. What is the term for the process of expelling waste materials from the body in the form of urine?
a. Filtration
b. Excretion
c. Absorption
d. Secretion
Answer: b. Excretion
11. Which of the following is the main nitrogenous waste product excreted by birds?
a. Ammonia
b. Urea
c. Uric acid
d. Creatinine
Answer: c. Uric acid
12. In which part of the nephron does the majority of tubular reabsorption occur?
a. Glomerulus
b. Proximal convoluted tubule
c. Distal convoluted tubule
d. Loop of Henle
Answer: b. Proximal convoluted tubule
13. Which of the following organs is not directly involved in the human excretory system?
a. Liver
b. Lungs
c. Spleen
d. Skin
Answer: c. Spleen
14. What is the role of the collecting duct in the nephron?
a. Filtration
b. Reabsorption
c. Secretion
d. Concentration of urine
Answer: d. Concentration of urine
15. Which substance is responsible for the yellow color of urine?
a. Urea
b. Creatinine
c. Bilirubin
d. Glucose
Answer: c. Bilirubin
16. Which hormone stimulates the release of aldosterone, promoting sodium reabsorption in the kidneys?
a. Cortisol
b. Thyroxine
c. Aldosterone
d. Insulin
Answer: c. Aldosterone
17. What is the function of the juxtaglomerular apparatus in the kidney?
a. Filtration
b. Blood pressure regulation
c. Tubular reabsorption
d. Urea secretion
Answer: b. Blood pressure regulation
18. Which of the following is a disorder characterized by the accumulation of nitrogenous waste in the blood due to kidney failure?
a. Diabetes mellitus
b. Nephritis
c. Uremia
d. Cystitis
Answer: c. Uremia
19. What is the primary role of the ureter in the excretory system?
a. Filtration
b. Storage of urine
c. Transportation of urine from the kidney to the bladder
d. Reabsorption
Answer: c. Transportation of urine from the kidney to the bladder
20. Which structure in the excretory system stores urine before it is expelled from the body?
a. Urethra
b. Bladder
c. Renal pelvis
d. Ureter
Answer: b. Bladder
21. Nitrogenous waste is excreted in the form of pellets or paste by
1. Pavo
2. Ornithorhynchus
3. Salamandra
4. Hippocampus
Answer – 1, Pavo
22. Which one of the following hormones reduces blood pressure?
1. Antidiuretic hormone
2. Atrial Natriuretic factor
3. Aldosterone
4. Angiotensin-ll
Answer – 2, Atrial Natriuretic factor
23. The normal value of GFR is approximate:
1. 650 ml/min
2. 180 ml/min
3. 180 ml/day
4. 125 ml/min
Answer – 4, 125 ml/min
24. What is used as an osmolyte in human beings to increase medullary interstitial osmolality during urine concentration?
1. TMAO
2. Urea
3. Both a and b
4. Uric acid
Answer – 2, Urea
25. The proximal convoluted tubule is lined by the following:
1. Simple cuboidal epithelium
2. Simple columnar epithelium
3. Simple cuboidal brush-bordered epithelium
4. Simple columnar brush-bordered epithelium
Answer – 3, Simple cuboidal brush-bordered epithelium
26. Which of the following factors contributes to the formation of concentrated urine?
1. Hydrostatic pressure during glomerular filtration.
2. Low levels of antidiuretic hormone.
3. Maintain hyperosmolarity to the inner pontomedullary stroma.
4. Secretion of erythropoietin by the juxtaglomerular complex.
Answer – 2, Low levels of antidiuretic hormone
27. Which of the following statements is incorrect?
1. ADH prevents the conversion of angiotensinogen in blood to angiotensin
2. Aldosterone promotes water reabsorption
3. NF promotes sodium reabsorption
4. Renin causes vasodilation
Answer – 3, ANF promotes sodium reabsorption
28. A fall in glomerular filtration rate (GFR) activates
1. Posterior pituitary to release vasopressin
2. Adrenal medulla releases adrenaline
3. Juxtaglomerular cells to release renin
4. Adrenal cortex to release aldosterone
Answer – 3, juxtaglomerular cells to release renin
29. The cone-shaped kidney tissue is called ____.
1. Renal Pelvis
2. Renal Calculi
3. Renal Pyramids
4. Renal Vasculitis
Answer – 3, Renal Pyramids
30. Vasa recta in cortical nephrons:
1. Arises from afferent arteriole rather than efferent arteriole
2. Does not get involved in the counter-current exchange with the loop of Henle
3. Carries deoxygenated blood rich in urea
4. Is absent or highly reduced
Answer – 4, Is absent or highly reduced
31. What is the condition of urea accumulation in the blood?
1. Renal calculi
2. Glomerulonephritis
3. Uremia
4. Ketonuria
Answer – 3, Uremia
32. Which one of the following is also known as an antidiuretic hormone?
1. Oxytocin
2. Vasopressin
3. Adrenaline
4. Calcitonin
Answer – 2, Vasopressin
33. What is most likely the cause of albumin appearing in urine?
1. Increase in blood pressure.
2. Decrease in the blood osmotic corpuscles
3. Damage to the Malpighian corpuscles
4. Damage to the proximal convoluted tubules
Answer – 3, Damage to the Malpighian corpuscles
34. What is the content of glomerular filtrate?
1. Urea, sodium chloride, fibrinogen, and water
2. Glucose, amino acids, urea, oxytocin, and calcitonin
3. Both (1) and (2)
4. Urea, glucose, salts, and water
Answer – 4, Urea, glucose, salts, and water
35. “Columns of Bertini” are formed in the kidneys of mammals by extending?
1. Medulla into the cortex
2. Cortex into the medulla
3. Medulla into the pelvis
4. Pelvis into the ureter
Answer – 2, Cortex into the medulla