Bachelor of Pharmacy (B.Pharm.) Human Anatomy & Physiology Flashcards

The blood-brain barrier is primarily formed by:

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.

Which cells in the testes are responsible for testosterone production?

Answer: Leydig (interstitial) cells

Leydig cells in the interstitial tissue of the testes synthesize and secrete testosterone under LH stimulation.

Frank-Starling law of the heart states that:

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.

Which part of the brain integrates sensory input to coordinate balance, muscle tone, and fine motor movements?

Answer: Cerebellum

The cerebellum compares intended with actual movement, adjusting motor output to coordinate precise, smooth motions.

The primary site of absorption of most nutrients and water-soluble vitamins in the gastrointestinal tract is the:

Answer: Small intestine (jejunum primarily)

The jejunum, with its vast surface area from villi and microvilli, absorbs the majority of digested nutrients.

During exercise, increased CO2 production in muscles causes local capillary beds to:

Answer: Vasodilate, increasing blood flow to working muscle

Local hypercapnia and acidosis cause precapillary sphincter relaxation, increasing perfusion of actively metabolizing tissue.

Parathyroid hormone (PTH) raises blood calcium primarily by acting on which organ to stimulate calcium reabsorption?

Answer: Kidney (distal tubule)

PTH acts on the distal convoluted tubule to increase Ca2+ reabsorption and on bone to stimulate osteoclast activity.