6 The Cardiovascular System Free Online FlashCards

What are the three main components of the cardiovascular system?

The heart, blood, and blood vessels move oxygen, nutrients, hormones, heat, and wastes through the body.

What does the heart’s septum separate?

The septum separates the heart’s right side from its left side.

How do the functions of atria and ventricles differ?

The atria receive blood; the ventricles pump blood out of the heart.

What do the four heart valves do, and where are they located?

The valves keep blood moving one way: tricuspid, right atrium to right ventricle; pulmonary, right ventricle to pulmonary trunk; mitral, left atrium to left ventricle; aortic, left ventricle to aorta.

Why does the left ventricle have a thick muscular wall?

Its thick muscular wall helps it generate enough pressure to propel blood through the body.

What defines an artery, and what helps its walls withstand pressure?

Arteries carry blood away from the heart; their relatively thick, elastic walls withstand the heart’s pumping pressure.

How does changing arteriole diameter affect blood flow?

Arterioles adjust their diameter. Narrowing increases resistance and can reduce flow; widening can increase flow.

What exchange takes place across capillary walls?

Their thin walls allow oxygen, nutrients, and other substances to move between blood and tissues, while carbon dioxide and some wastes enter the blood.

How do venules and veins move blood?

Venules collect blood from capillaries and carry it toward veins. Veins return blood to the heart; many have valves that help prevent backward flow.

How do the pulmonary and systemic circuits differ?

The pulmonary circuit carries blood from the heart to the lungs and back. The systemic circuit carries it from the heart to body tissues and back.

What is unusual about the oxygen content of pulmonary artery and vein blood?

Pulmonary arteries carry oxygen-poor blood to the lungs; pulmonary veins carry oxygen-rich blood back to the heart.

What is plasma, and what does it carry?

Plasma is the liquid portion of blood. It carries water, dissolved substances, and proteins.