Cardiovascular+System+DB

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

(2) What are the functions of the cardiovascular system? The functions of the cardiovascular system include: oxygen and CO2 exchange to refresh the blood at the capillaries, regulation of the blood flow of the body, transportation of blood through arteries, veins, and capillaries, and contractions of the heart to move blood.

(3) What are the types of blood vessels? (4) What is the structure and function of these vessels? Arteries are blood vessels that consist of three layers and move blood away from the heart and into the body. Capillaries are blood vessels that are very narrow and have walls consisting of a single layer of cells. The capillaries are able to diffuse oxygen and carbon dioxide across their thin walls. Veins are similar to arteries in that they have three layers of tissue in their walls, but the walls of veins are a little thinner, allowing them to expand and hold more blood. Veins carry blood from the body into the heart.

(5) Why is the heart a double pump? The heart is a double pump because its left ventricle, which has thick muscular walls, sends blood throughout the body, while the right ventricle sends blood to the lungs.

(6) What causes the "lub" and the "dup" of the heart sounds? The “lub” sound is created when blood rushes into the ventricle and causes the AV valve to shut quickly. The “dup” sound happens when the ventricles relax and blood flow causes semilunar valves to close.

(7) What keeps the heart beat regular? A person’s heart beat is regulated internally by the SA node, or pacemaker using electrical currents between cells. A heart beat is controlled externally by the “fight or flight” response which causes it to pump harder in times when the hormones epinephrine and norepineprhine are released.

(8) What does the pulse rate of a person indicate? The pulse rate of a person indicates how fast or slow he or she’s heart is beating.

(9) What accounts for blood flow in the arteries? Blood flow in the arteries is accounted for by blood pressure, or the pressure of blood against the wall of a blood vessel.

(10) What accounts for blood flow in the veins? The skeletal muscle pump, the respiratory pump, and valves in veins cause blood flow in the vessels.