B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) Human Anatomy & Physiology 4 — Questions and Answers
Question 1: The blood-brain barrier is primarily formed by:
- Microglia with phagocytic processes
- Tight junctions between capillary endothelial cells and astrocyte end-feet (Correct answer)
- Myelin sheaths surrounding cerebral vessels
- Ependymal cells lining the ventricles
Correct answer: Tight junctions between capillary endothelial cells and astrocyte end-feet
Tight junctions between brain capillary endothelial cells, reinforced by astrocyte end-feet, form the BBB restricting molecular passage.
Question 2: Which cells in the testes are responsible for testosterone production?
- Sertoli cells
- Spermatogonia
- Leydig (interstitial) cells (Correct answer)
- Primary spermatocytes
Correct answer: Leydig (interstitial) cells
Leydig cells in the interstitial tissue of the testes synthesize and secrete testosterone under LH stimulation.
Question 3: Frank-Starling law of the heart states that:
- Heart rate increases proportionally with stroke volume
- Greater ventricular filling during diastole results in greater force of contraction (Correct answer)
- Peripheral resistance is inversely related to cardiac output
- Systolic pressure equals cardiac output times heart rate
Correct answer: Greater ventricular filling during diastole results in greater force of contraction
Increased end-diastolic volume stretches ventricular muscle fibers, producing a more forceful contraction and greater stroke volume.
Question 4: Which part of the brain integrates sensory input to coordinate balance, muscle tone, and fine motor movements?
- Cerebral cortex
- Hypothalamus
- Cerebellum (Correct answer)
- Basal ganglia
Correct answer: Cerebellum
The cerebellum compares intended with actual movement, adjusting motor output to coordinate precise, smooth motions.
Question 5: The primary site of absorption of most nutrients and water-soluble vitamins in the gastrointestinal tract is the:
- Stomach
- Duodenum only
- Small intestine (jejunum primarily) (Correct answer)
- Large intestine
Correct answer: Small intestine (jejunum primarily)
The jejunum, with its vast surface area from villi and microvilli, absorbs the majority of digested nutrients.
Question 6: During exercise, increased CO2 production in muscles causes local capillary beds to:
- Vasoconstrict to divert blood to vital organs
- Vasodilate, increasing blood flow to working muscle (Correct answer)
- Release epinephrine from adrenal medulla
- Increase platelet aggregation
Correct answer: Vasodilate, increasing blood flow to working muscle
Local hypercapnia and acidosis cause precapillary sphincter relaxation, increasing perfusion of actively metabolizing tissue.
Question 7: Parathyroid hormone (PTH) raises blood calcium primarily by acting on which organ to stimulate calcium reabsorption?
- Stomach
- Small intestine
- Kidney (distal tubule) (Correct answer)
- Liver
Correct answer: Kidney (distal tubule)
PTH acts on the distal convoluted tubule to increase Ca2+ reabsorption and on bone to stimulate osteoclast activity.
B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) Human Anatomy & Physiology 4
The blood-brain barrier is primarily formed by: