HSC 3537 Lecture Notes - Lecture 11: Atrioventricular Node, Pulmonary Valve, Heart
Document Summary
Introduction: cardiovascular system: delivers oxygen and nutrients to cells of body tissue. Blood vessels (fuel line and transportation network) Blood vessels and the circulation of blood: arteries are the vessels that lead away from the heart, veins have thinner walls than arteries and move deoxygenated blood toward the heart from the tissues, capillaries are the smallest vessels. They form the point of exchange for oxygen and nutrients into body cells and waste products coming from body cells. Two phases of the heartbeat: diastole: relaxation. The diastole-systole cardiac cycle occurs between 70 to 80 times per minute (100,000 times per day). The heart pumps 3 ounces of blood with each contraction. This means that about 5 quarts are pumped per minute (75 gallons an hour and about 2000 gallons a day). Sinoatrial node (sa node): the pacemaker of the heart (60-100 impulses)
