arrow_backBack to Study Resources

Quiz Chapter 13: Homeostasis and the Human Urinary System

10 questions · Form 4 Biology Bab 13: Homeostasis and the Human Urinary System

10 questions · plays in fullscreen

Full Question List & Answer Key

Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.

1. Which component of blood does NOT pass through the glomerular filtration barrier during normal ultrafiltration?

  1. A. Urea
  2. B. Plasma proteins (e.g., albumin)
  3. C. Glucose
  4. D. Sodium ions
Show answer

Answer: B

Large macromolecules like plasma proteins and blood cells cannot pass through the filtration slits of the glomerulus due to their size.

2. What primary mechanism allows ultrafiltration to occur within the glomerulus of the nephron?

  1. A. High hydrostatic pressure caused by the afferent arteriole having a larger diameter than the efferent arteriole
  2. B. Active transport of blood proteins across the glomerular membrane
  3. C. Low osmotic pressure in the peritubular capillary network
  4. D. Selective pinocytosis by podocyte epithelial cells
Show answer

Answer: A

The difference in diameter between the wider afferent arteriole and narrower efferent arteriole creates high hydrostatic pressure in glomerular capillaries, forcing fluid into Bowman's capsule.

3. Where does 100% of useful filtered nutrients, such as glucose and amino acids, get reabsorbed back into the bloodstream under normal healthy conditions?

  1. A. Descending limb of Loop of Henle
  2. B. Proximal convoluted tubule
  3. C. Distal convoluted tubule
  4. D. Collecting duct
Show answer

Answer: B

The proximal convoluted tubule actively reabsorbs all filtered glucose and amino acids back into the surrounding peritubular capillaries.

4. Which physiological mechanism contributes to heat loss when body temperature rises?

  1. A. Shivering of skeletal muscles
  2. B. Contraction of erector muscles
  3. C. Evaporation of sweat from skin surface
  4. D. Secretion of adrenaline by adrenal medulla
Show answer

Answer: C

Sweat evaporation absorbs latent heat of vaporization from the skin, efficiently cooling the body.

5. Which hormone is secreted by the adrenal cortex to stimulate sodium ion (Na⁺) reabsorption in the renal tubules?

  1. A. Aldosterone
  2. B. Antidiuretic hormone (ADH)
  3. C. Oxytocin
  4. D. Cortisol
Show answer

Answer: A

Aldosterone targets the distal convoluted tubule and collecting duct to increase Na+ reabsorption when blood sodium or blood pressure is low.

6. Diabetes insipidus is a disorder caused by an inability of the body to produce or respond to which hormone?

  1. A. Insulin
  2. B. Antidiuretic hormone (ADH)
  3. C. Glucagon
  4. D. Aldosterone
Show answer

Answer: B

Deficiency of ADH prevents water reabsorption in distal tubules, causing Diabetes Insipidus characterized by excessive excretion of dilute urine.

7. A rise in carbon dioxide concentration ($pCO_2$) in the blood leads directly to which physiological change?

  1. A. Increase in blood pH (alkalosis)
  2. B. Decrease in blood pH (acidosis)
  3. C. Inhibition of the respiratory centre
  4. D. Vasoconstriction of pulmonary capillaries
Show answer

Answer: B

CO2 reacts with water to form carbonic acid ($H_2CO_3$), which dissociates into $H^+$ ions, lowering blood pH.

8. What is the effect of erector muscles relaxing during hot weather?

  1. A. Hairs stand upright to trap a thick layer of still air.
  2. B. Hairs lie flat, preventing air from being trapped next to the skin so heat escapes easily.
  3. C. Sweat production is immediately halted.
  4. D. Subcutaneous fat layers melt away.
Show answer

Answer: B

When erector muscles relax, hair follicles lie flat against the skin surface, reducing the trapped insulating layer of still air.

9. Which nephron segment connects the proximal convoluted tubule directly to the distal convoluted tubule?

  1. A. Bowman's capsule
  2. B. Glomerulus
  3. C. Loop of Henle
  4. D. Collecting duct
Show answer

Answer: C

The hairpin-shaped Loop of Henle extends down into the renal medulla, connecting proximal and distal convoluted tubules.

10. What is the primary action of glucagon when blood glucose levels fall below normal?

  1. A. Stimulating liver cells to convert glycogen into glucose
  2. B. Increasing rate of glucose uptake in skeletal muscle cells
  3. C. Promoting storage of excess glucose into fat tissue
  4. D. Inhibiting gluconeogenesis in liver tissues
Show answer

Answer: A

Glucagon secreted by pancreatic alpha cells accelerates glycogenolysis (breakdown of glycogen to glucose) in the liver to elevate blood glucose.

Sponsored