The Human Heart– Structure

Interesting Facts In your lifetime, your heart beats about 3 billion times without a single break The aorta, the largest artery in your body, is almost the diameter of a garden hose The heart pumps about 1 million barrels of blood during an average lifetime

Anatomy of the Heart The Pericardium Structure a double wall sac covering the heart Function protects and anchors the heart provides a friction-free environment Figure 13.2

Anatomy of the Heart Four Chambers Right and Left Atrium Think 4’s! Four Chambers Right and Left Atrium Right and Left Ventricle -separating the chambers is the septum Four Vessels Inferior/Superior Vena Cava and Aorta Pulmonary Artery and Pulmonary Vein Four Valves Tricuspid and Bicuspid Valve Pulmonary and Aortic Semilunar Valve

Anatomy of the Heart Review Heart Anatomy Here Figure 13.4

Flow of Blood Through the Heart Right side of the heart pumps deoxygenated blood to the lungs Pulmonary circuit Figure 13.6

Flow of Blood Through the Heart Left side of the heart pumps oxygenated blood to the body Systemic circuit Figure 13.6

Click here to see how the blood flows through the heart! Flow of Blood Through the Heart Atria pump together Ventricles pump together Valves between chambers direct blood flow in proper sequence Click here to see how the blood flows through the heart! Figure 13.6

Pathway of Blood – Pulmonary and Systemic Circuits R. Atrium R. Ventricle Pulmonary Artery BCV PSLV Vena Cava Lungs Aorta ASLV TCV L. Ventricle L. Atrium Pulmonary Vein

Heart Valves Blood flows through the heart in one direction. Heart valves open and close to prevent the backflow of blood within the heart. The valves open and close in response to differences in blood pressure. Figure 13.5

Heart Valves Atrioventricular (AV) valves (bicuspid and tricuspid) Prevent backflow into atria when ventricles are contracting Chordae tendinae and papillary muscles anchor and hold valve flaps when closed

Heart Valves Semilunar (SL) valves Prevent backflow into ventricles when ventricles relax Flaps are small cups, shaped like ‘half moon’ Lack chordae tendinae of the AV valves, because they close under less pressure Click here to see how the valves work