PAX Physiology

Question 1

The sinoatrial (SA) node is the heart's natural pacemaker. Where is it located?

Accepted Answer

Right atrium

Answer

The SA node is located in the right atrium and generates the electrical impulses that initiate each heartbeat.

Question 2

Which blood vessels carry oxygenated blood away from the heart in systemic circulation?

Accepted Answer

Arteries

Answer

Arteries carry oxygenated blood away from the heart to body tissues in systemic circulation.

Question 3

During inhalation, what happens to the diaphragm?

Accepted Answer

It contracts and moves downward

Answer

During inhalation, the diaphragm contracts and flattens downward, increasing thoracic volume and drawing air into the lungs.

Question 4

Which molecule in red blood cells binds to oxygen for transport throughout the body?

Accepted Answer

Hemoglobin

Answer

Hemoglobin is the iron-containing protein in red blood cells that binds oxygen in the lungs and releases it in body tissues.

Question 5

What is the normal resting heart rate range for a healthy adult?

Accepted Answer

60–100 beats per minute

Answer

A normal resting heart rate for adults is 60–100 beats per minute; below 60 is bradycardia and above 100 is tachycardia.

PAX - Pre-Admission Examination Practice Test