Your Majestic Pump: The Human Heart APL3

Cardiovascular system Composed of: Heart Blood vessels ( arteries, veins, capillaries) Vital for circulation: circulating oxygen to body and toxins (wastes) out

Cardiac Output (Performance) Stroke volume: 80ml at rest Heart Rate: 70 bpm at rest; 180 during exercise Cardiac Output: SV * HR = 5600 ml/min Total blood volume is approx 5-6 liters. Your heart pumps almost entire volume of blood throughout body in 1 minute!

Your incredible engine! How much gas would the average car pump in its life? Blood pumped in 70 years: 206 million liters, or 50 million gallons Most efficient engine ever made Typical hybrid car (60mpg) New cars (26.5 mpg)

Coverings of the Heart Double layered Pericardium Visceral: inner, delicate lining on surface of heart Parietal: outer, tough sac fitting loosely around heart Pericardial cavity: space between 2 layers. Filled with fluid to friction

Wall of heart: 3 Layers Epicardium: protective outer membrane Myocardium: middle, heart wall, rich in blood Cardiac muscle Endocardium: inner lining of heart wall Purkinje fibers, collagen, elastin, BV’s

Heart chambers: Four 2 Atria: Thin walled upper chambers Receive blood 2 ventricles: Thick walled lower chambers Pump blood out R. & L. sides separated by septum

One way blood flow: Valves One set separates the atria & ventricles Tricuspid: (3 cusps) Separates Right atria and R. ventricle Bicuspid: (2 cusps) Left atria & L. ventricle

Valves cont’ Semilunar valves: separate the ventricles from the exits of the heart Pulmonary SL valve separates R ventricle from the pulmonary artery Aortic SL valve separates L. ventricle from the aorta