IMAT - International Medical Admissions Human Anatomy and Physiology Questions and Answers

Question 1

Which of the following correctly sequences the path of a deoxygenated red blood cell returning from the systemic circulation to the lungs?

Accepted Answer

Vena cava -> Right atrium -> Right ventricle -> Pulmonary artery

Answer

Left atrium -> Left ventricle -> Aorta -> Lungs

Answer

Pulmonary vein -> Left atrium -> Left ventricle -> Pulmonary artery

Answer

Vena cava -> Left atrium -> Right atrium -> Lungs

Question 2

A patient's blood glucose level rises significantly after a meal. Which of the following represents the correct physiological negative feedback response to this stimulus?

Accepted Answer

The pancreas releases insulin, stimulating cells to take up glucose from the blood.

Answer

The pancreas releases glucagon, stimulating the liver to release glucose.

Answer

The adrenal gland releases adrenaline, causing a rapid breakdown of glycogen.

Answer

The pituitary gland releases growth hormone, promoting glucose synthesis.

Question 3

The chemical digestion of proteins begins in which organ, and by which primary enzyme?

Accepted Answer

Stomach, by pepsin

Answer

Small intestine, by trypsin

Answer

Mouth, by amylase

Answer

Liver, by bile

Question 4

In the sliding filament model of skeletal muscle contraction, what is the direct role of calcium ions (Ca2+)?

Accepted Answer

To bind to troponin, causing tropomyosin to move and expose actin binding sites.

Answer

To provide the energy for the power stroke.

Answer

To bind to myosin heads, causing them to detach from actin.

Answer

To break down ATP into ADP and phosphate.

Question 5

Following the repolarization phase of a neuron's action potential, what is the primary function of the Na+/K+ pump?

Accepted Answer

To restore the resting ion concentration gradients by moving Na+ out and K+ into the cell.

Answer

To generate the initial depolarization stimulus for the next action potential.

Answer

To close the voltage-gated K+ channels to prevent hyperpolarization.

Answer

To open voltage-gated Na+ channels to initiate a new impulse.

Question 6

In the human respiratory system, the net diffusion of oxygen from the alveoli into the pulmonary capillaries is primarily driven by:

Accepted Answer

The higher partial pressure of oxygen in the alveolar air compared to the capillary blood.

Answer

Active transport mechanisms that pump oxygen across the respiratory membrane.

Answer

The higher temperature of the blood, which increases oxygen's solubility.

Answer

The binding affinity of carbon dioxide for hemoglobin.