Physiology Flashcards

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

Answer: Right atrium

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

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

Answer: Arteries

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

During inhalation, what happens to the diaphragm?

Answer: It contracts and moves downward

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

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

Answer: Hemoglobin

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

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

Answer: 60–100 beats per minute

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

Gas exchange in the lungs — oxygen entering the blood and carbon dioxide leaving — occurs in which structures?

Answer: Alveoli

Alveoli are tiny air sacs where oxygen diffuses into the blood and carbon dioxide diffuses out, making them the primary site of gas exchange.

What term describes the total volume of blood pumped by the heart per minute?

Answer: Cardiac output

Cardiac output is the volume of blood the heart pumps per minute, calculated as heart rate multiplied by stroke volume.