Cardio vascular system Heart Located in the mediastinum space between the lungs and of the thoracic cavity Apex is closest to the diaphragm Base is closet to the clavicle bones 3 layers form the heart Endocardium inner layer of the heart Myocardium middle layer provides contractility Pericardium outermost layer of the heart protective Fibrous pericardium Parietal pericardium Visceral pericardium also called epicardium Arteries away from the heart Systemic arteries are generally red aorta Pulmonary arteries are generally blue contain deoxygenated blood Veins return back to the heart Systemic veins are generally blue Pulmonary veins 4 red 3 types of blood circulation Systemic circuit flows throughout body aorta to all body cells body cells to superior vena cava and inferior vena cava Pulmonary circuit only transports heart to lungs and lungs back to heart pulmonary trunk Coronary circuit provides the heart proper with blood Coronary arteries first to come off the aorta and delivers oxygenated blood to heart The Vein in coronary circulation that delivers deoxygenated blood to the right atrium is the coronary sinus Atria right and left are receiving chambers of the heart Ventricles right and left are pumping chambers Right side of heart always contains deoxygenated blood Left side of heart always contains oxygenated blood Parasympathetic NS 75 BPM Sympathetic NS medulla oblongata of brain stem maintains sympathetic control the cardio acceleratory and cardioinhibitory center Nerve supply to heart Heart values A V value Tricuspid and Bicuspid or mitral Have papillary muscles and chordae tendinea associated with them Semilunar valves pulmonic and aortic Prevent the backflow to the pulmonary trunk and aorta They do not have papillary muscles and chordae tendineae Blood 0always moves from higher pressure to lower pressure Bicuspid valves prevent the backflow of blood from the left ventricle to the left atrium Tricuspid valves prevent the backflow of blood from the right ventricle to the right atrium Cardiac cycle Ventricular filling AV valves are open Ventricles fill due first to gravity then due to increases pressure as the atrial myocardium contracts Ventricular systole Ventricular diastole Isovolumetric same volume of blood contraction When this phase is complete we can measure end systolic volume approximates 50 mL of blood ESV is the volume of blood in ventricles at the end of ventricular systole Isovolumetric relaxation When the phase is complete we can measure end diastolic volume EDV approximates 120 mL of blood EDV is the volume of blood in the ventricles at end of ventricular diastole Heart sounds heard during cardiac 1st sound 2nd sound Closing of the AV valves bicuspid and tricuspid Closing of the semilunar valves pulmonary and aortic Both together make up the lubb dupp sound Electrical conduction system Is separate from the cardiac cycle Occurs first before the cardiac cycle involves autorhythmic in heart autorhythmic signals are produced by special cardiac muscle cells called nodes not nerve cells but muscles cells that depolarize spontaneously on their own the primary pacemaker of the heart is the SA or sinoatrial node 100 BPM the SA node is found in the superior end of the right atrium aa