BSC 109 1st Edition Lecture 12 Outline of Last Lecture I. Clotting DisordersII. Human Blood TypesIII. Blood typing and cross- matching ensure blood compatibilityIV. Blood DisordersCHAPTER 8I. Blood vessels transport bloodII. Arteries transport blood away from the heartIII. Capillaries: where blood exchanges substances with tissuesOutline of Current Lecture III. Lymphatic system helps maintain blood volumeIV. Veins return blood to the heartV. The heart is mostly muscleVI. The heart has four chambers and four valvesVII. The pulmonary circuit provides for gas exchangeVIII. The systemic circuit serves the rest of the bodyIX. The cardiac cycle: the heart contracts and relaxesX. Heart sounds reflect closing heart valvesXI. Cardiac conduction system coordinates contractionXII. Electrocardiogram (EKG/ECG) XIII. Blood exerts pressure against vessel wallsXIV. Hypertension: high blood pressure can be dangerousCurrent LectureXV. Lymphatic system helps maintain blood volumeA. Function: maintains blood volumeB. Structure: blind-ended capillaries; lymphatic vessels (similar to venous system); lymph: derived from interstitial fluidXVI. Veins return blood to the heartA. 3 layers, thin-walledB. Carries blood toward the heartC. Blood flows from capillaries to venules to veins to the heartD. Serves as blood volume reservoirE. 3 mechanisms assisting in blood returnThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. Contraction of skeletal muscles2. One-way valves permit only one-way blood flow3. Pressure changes associated with breathing push blood toward the heartXVII. The heart is mostly muscleA. Pericardium: fluid-filled fibrous sac surrounding the heartB. Layers of the heart1. Epicardium: thin layer of epithelial and connective tissue2. Myocardium: thick layer of cardiac muscle; electrical signals flow directly from cell to cell; this is what contracts when the heart beats3. Endocardium: thin layer of endothelial tissue; continuous with lining of blood vesselsC. Humans have a double circulation system1. One complete trip: one minutea) Requires two passes through the heartb) Pulmonary circuit between the hear and the lungsc) Systemic circuit between the heart and the rest of the bodyXVIII. The heart has four chambers and four valvesA. 4 chambers1. 2 atria: upper chambers2. 2 ventricles: lower chambersB. 4 valves- prevent backflow1. 2 atrioventricular valves2. 2 semilunar valvesa) Pulmonary valveb) Aortic valveC. *Know locations of: superior vena cava, right pulmonary artery, pulmonary semilunar valve, right atrium, right atrioventricular valve, right ventricle, inferior vena cava, aorta, left pulmonary artery, pulmonary trunk, left pulmonary valve, left atrium, aortic semilunar valve, left atrioventricular valve, left ventricle, septumD. Even the heart muscle needs bloodXIX. The pulmonary circuit provides for gas exchangeA. Deoxygenated blood: vena cava -> right atrium -> right ventricle ->pulmonary semilunar valve -> pulmonary trunk/ lungs *where blood is oxygenated, CO2 is given up within pulmonary capillariesB. Oxygenated blood: pulmonary veins -> left atrium -> left ventricleXX. The systemic circuit serves the rest of the bodyA. Oxygenated blood: left ventricle -> aortic semilunar valve -> aorta -> branching arteries/ arterioles -> tissues -> capillaries, where nutrients and oxygen are delivered and wastes are picked up -> venules/ veins -> vena cava/ right atriumB. Coronary arteries1. Arteries that supply the heart muscle itself2. Supply the myocardium3. Small diameter: may become partially or completely blocked by atherosclerosis: hardening of the arteriesXXI. The cardiac cycle: the heart contracts and relaxesA. Diastole: relaxation; Systole: contractionB. Atrial systole: both atria contract, AV valves open, semilunar valves close, ventricles fillC. Ventricular systole: both ventricles contract, AV valves close, semilunar valves openD. Diastole: both atria and ventricles relax, semilunar valves closeXXII. Heart sounds reflect closing heart valvesA. Lub: closing of both AV valves during ventricular contractionB. Dub: closing of both semilunar valves during ventricular diastoleC. Heart murmurs: caused when blood flow is disturbed, may be a sign of a defective valveXXIII. Cardiac conduction system coordinates contractionA. Sinoatrial node: small mass of cardiac cells in upper right atriumB. Cardiac pacemaker: initiates the heartbeat spontaneously, pace can be modified by nervous systemC. Atrioventricular node: located between atria and ventricles; relays impulseD. Atrioventricular bundle and Purkinje fibers: located in septum and ventricles, carry impulse to ventriclesXXIV. Electrocardiogram (EKG/ECG) A. Records the heart’s electrical activityB. Can detect arrhythmias and ventricular fibrillationXXV. Blood exerts pressure against vessel wallsA. Systolic pressure: highest pressure, as blood is ejected during ventricular systoleB. Diastolic pressure: lowest pressure, during ventricular diastoleC. 120/80 is normalD. Sphygmomanometer: device used to measure blood pressureE. Pulse: rhythmic stretching of the arteries caused by the pressure of blood forced into the arteries during systoleXXVI. Hypertension: high blood pressure can be dangerousA. “The silent killer,” no symptomsB. Sustained elevation in blood pressureC. Risk factor for cardiovascular