Week 3: Cardiovascular System

Cardiovascular system

Consists of heart, blood vessels, and blood; transports oxygen, hormones, and nutrients to cells and removes CO2 and waste.

Vasodilation

The widening of blood vessels to regulate body temperature.

Vasoconstriction

The narrowing of blood vessels to regulate body temperature.

Atria

The two upper chambers of the heart that act as low-pressure collecting chambers.

Ventricles

The two lower chambers of the heart that act as high-power pumps.

Interatrial septum

The wall separating the right and left atria.

Interventricular septum

The wall separating the right and left ventricles.

Tricuspid valve

The right atrioventricular valve with three cusps that prevents backflow into the right atrium.

Bicuspid/mitral valve

The left atrioventricular valve with two cusps that prevents backflow into the left atrium.

Chordae tendinae

Fibrous cords attached to valve cusps that prevent valve inversion.

Semilunar valves

Valves that control blood flow from the ventricles to the pulmonary artery and aorta.

Cardiac cycle

The series of events from one heartbeat to the next, including diastole (relaxation) and systole (contraction).

Preload

The stretch of ventricle muscles during diastole.

Contractility

The heart muscle's ability to contract.

Afterload

The pressure that must be overcome for the ventricles to eject blood.

Electrocardiogram (ECG)

A recording of the electrical activity of the heart.

Tunica intima

The innermost layer of blood vessels, providing a smooth frictionless surface.

Tunica media

The middle layer of blood vessels, consisting of smooth muscle that regulates diameter.

Tunica externa

The outer layer of blood vessels, made of fibrous tissue that provides support.

Capillaries

The smallest blood vessels where gas exchange occurs.

Pulmonary circulation

The flow of blood from the heart to the lungs and back to the heart.

Systemic circulation

The flow of blood from the heart to the rest of the body and back to the heart.

Aorta

The largest artery in the body that carries oxygenated blood from the left ventricle.

Coronary arteries

Arteries that supply oxygen-rich blood to the heart tissue.