EMI Huang: First third of NED CIRC NOTES 2009 Systole: Heart ventricles contract/chamber pump Diastole: Heart ventricles relax/chamber fills AIM: What are the parts of the heart and blood? William Harvey established direction of blood flow and elucidated difference between pulmo and systemic circulation. TYPES OF CIRCULATION: Pulmonary: travel of blood between heart and lungs Coronary: supplies blood to heart Renal: supplies blood to kidneys Hepatic portal: supplies liver with nutrients; receive oxygenated blood from the aorta HEART: CHAMBERS AND VALVES Atria: blood into upper chambers Ventricles: blood out of lower chambers. Valves/regulated one-way flow. A/V: Atria Ventricular S/L: Semilunar (Valves separate chambers, preventing blood from mixing) 2 A/V valves separate atria from ventricles 1. Right A/V: tricuspid (3 teeth) 2. Left A/V: bicuspid or mitral 2 S/L valves regulate flow from ventricle to vessel 1. Right S/L: pulmonary 2. Left S/L: aortic FLOW IN VESSELS AND CHAMBERS Aorta: major artery carrying blood from heart Vena cava(e): empty deoxygenated blood into right atrium Pulmonary artery: leaves right ventricle and carries blood to lungs Pulmonary veins: returns oxygenated blood from lungs to left atrium Left side [of chamber]: delivers blood to systems (systemic) Right side [of chamber]: delivers blood to lungs (pulmonary) NODES: STIMULUS TIMING Cardiac muscle contracts in syncitium. Nodes stimulate atria and ventricles to act together. SA (Sinoatrial) node: located in right atrium—is considered ‘pacemaker.’ Atria contract together. AV (Atrioventricular) node: located in septum (wall) between atria—delays ventricle contraction until ventricles fill with blood. -Harvey (17th century)- discovered veins-toward and arteries-away. -Previously, Galen’s predominate idea that blood ebbed and flowed without direction had taken hold. -Harvey challenged authority—did a dissection experiment—artery cut—blood spurts from and near heart (artery flow from heart). Vein cut—blood flows from end farther from heart, inward or forward. -Capillaries were harder to study—Malpighi discovered them in 1661; wanted for instruments.