The Heart 2 muscular pumps in one: - left heart pumps blood to the body tissues

1. The Heart • 2 muscular pumps in one: - left heart pumps blood to the body tissues - right heart pumps blood to the lungs The heart circulates the blood through the circulatory system. Blood carries oxygen and nutrients to cells

2. Anatomy of the Heart • Consists of 4 chambers - 2 atria – superior chambers, thin walls - 2 ventricles – inferior chambers, thicker walls • Valves - Tricuspid – separates right atrium and right ventricle - Bicuspid – separates left atrium and left ventricle Valves direct the flow of blood and prevents any backflow Heart murmur – if a valve is damaged or does not close properly, blood leaks backwards, causing a “noise”

4. The Path of Blood in the Heart • Enter Right Atrium from superior and inferior vena cava (largest veins in body) • Right atrium to the right ventricle through tricuspid valve • Right ventricle through pulmonary semilunar valve into pulmonary arteries • Pulmonary arteries to lungs (gets oxygen) • Exit lungs via pulmonary veins • Pulmonary veins into left atrium • Left atrium into left ventricle through bicuspid valve • Left ventricle into aorta through semilunar valve Aorta is the largest artery in the body

6. Blood is forced out of the ventricles with each heartbeat – walls of the left ventricle are thicker • Cardiac Output – volume of blood pumped by left ventricle per minute (5 L) • Stroke volume – volume of blood pumped by each ventricle per minute

7. Websites • http://www.kbtx.com/news/features/9/1112742.html • http://stjosephaspirin.com/