Blood flow through the heart: - ANS-1-Superior & Inferior Vena Cava, 2-Rt Atrium, 3- Tricuspid Valve, 4- Rt Ventricle, 5-Pulmonary Valve, 6-Pulmonary Artery, 7- Lungs-pick up oxygen, 8-Pulmonary Veins, 9- Lt Atrium, 10- Mitral Valve (Bicuspid), 11-Lt Ventricle, 12- Aortic Valve, 13-Aorta, 14- Body tricuspid valve - ANS-valve between the right atrium and the right ventricle mitral valve - ANS-located between the left atrium and left ventricle pulmonic valve - ANS-Heart valve between the RV and pulmonary artery aortic valve - ANS-heart valve between the left ventricle and the aorta AV valves: - ANS-tricuspid and mitral close during diastole to help prevent backflow or valvular regurgitation semilunar valves - ANS-pulmonary valve and aortic valve prevent blood from back flowing into the ventricles during diastole MAP - ANS-mean arterial pressure must be at least 60 mm Hg to maintain adequate blood flow through coronary arteries and to perfuse organs (brain) 60-70 is normal How to measure MAP - ANS-CO x SVR diastolic BP multiply by 2 add to systolic BP and then divide it by 3 Diastole - ANS-Relaxation of the heart systole - ANS-Contraction of the heart heart contraction - ANS-impulse to beat starts at the SA node the impulse goes to the AV node. It enters the ventricular system and follows a path of His and Perkinje fibers on both ventricular walls. ventricles then contact. during contraction blood is forced out through the systemic circulation and perfuses the entire body with oxygenated blood. Cardiac output - ANS-heart rate x stroke volume amount of blood pumped by the left ventricle in a minute average 4-7L/min What affects stroke volume? - ANS-HR, preload, afterload, contractility heart rate - ANS-A measure of cardiac activity usually expressed as the number of beats per minute. stroke volume - ANS-The amount of blood ejected from the heart in one contraction. HR, contractility affect SV Preload definition - ANS-volume of blood in ventricles at end of diastole stretching how much blood returns from the heart (right and left side) Impedance Cardiac - ANSAfterload - ANS-The force or resistance against which the heart pumps. door opening and closing What is afterload affected by? - ANS-1. the size of the ventricle 2. wall tension 3. arterial blood pressure What is preload affected by? - ANS-venous blood pressure and rate of venous return blood pressure regulation - ANS-brain stem: medulla oblongata What affects Blood pressure - ANS-- blood volume - stroke volume - total peripheral resistance - heart rate > increase in any of these will increase blood pressure blood pressure - ANS-the pressure that is exerted by the blood against the walls of blood vessels systolic blood pressure - ANS-the pressure created in the arteries when the left ventricle contracts and forces blood out into circulation indicator of vascular tone diastolic blood pressure - ANS-the pressure in the arteries when the left ventricle is refilling How does ANS regulate Blood pressure - ANS-excite or inhibit the sympathetic nervous system -baroreceptors are located on the aortic arch of your aorta and they are stimulated when your arterial walls are stretched by an increase in blood pressure chemoreceptors are broken down into peripheral chemoreceptors and central chemoreceptors so your peripheral chemoreceptors are in your carotid artery and aortic arch. They are sensitive to hypoxemia. RAAS system - ANS-Renin is produced by the kidneys in response to impaired blood flow & tissue perfusion, and converts angiotensinogen in the blood to angiotensin I; ACE converts angiotensin I to angiotensin II in the lungs. Angiotensin II then vasoconstricts and stimulates the release of aldosterone. Aldosterone then promotes Na and water retention as well as K excretion. Serum markers of myocardial damage: - ANS----Troponin—Troponin T and troponin I=Best indicator *Seen within 1-2 hours* ---Creatine kinase (CK) *12-24 hours*