Cardiovascular+System+hw-+kat

(1) What are the two parts of the cardiovascular system? The two parts of the cardiovascular system are the heart and the blood vessels.

(2) What are the functions of the cardiovascular system? The functions of the cardiovascular system include:
 * contractions of the heart generate blood pressure, which moves the blood through blood vessels
 * blood vessels transport the blood, which moves from the heart into arteries, capillaries, and veins, before returning back to the heart
 * exchanges at the capillaries refresh the blood and then tissue fluid, sometimes called **interstitial fluid**.
 * the heart and blood vessels regulate blood flow, according to the needs of the body.

(3) What are the types of blood vessels? The types of blood vessels we have are arteries, capillaries, and veins.

(4) What is the structure and function of these vessels? The structure of an artery has three layers. The innermost layer is a then layer of cells called **endothelium**, the middle layer is relatively thick of muscle, and the other layer is connective tissue. Arteries are the blood vessels that pump blood from the heart. The structure of capillary is made up of one thin layer of endothelium. Capillaries exchange blood. The structure of a vein is the same as an artery, but the walls are thinner. Veins pump blood to the heart.

(5) Why is the heart a double pump? The serves as a double pump because the right ventricle of the heart sends blood through the lungs, and the left ventricle sends blood throughout the body.

(6) What causes the "lub" and the "dup" of the heart sounds? The "lub" sound occurs when increasing pressure of the blood inside the ventricle forces the cusps of the AV valve to slam shut. The "dup" sound occurs when the ventricles relax, and blood in the arteries pushes back, causing the semilunar valves to close.

(7) What keeps the heart beat regular? The **SA (sinoatrial) node** keeps the heart beat regular.

(8) What does the pulse rate of a person indicate? The pulse rate of a person indicates the person's heart rate.

(9) What accounts for blood flow in the arteries? Blood pressure accounts for the flow in the arteries.

(10) What accounts for blood flow in the veins? Skeletal muscle pump accounts for the blood flow in the veins.