Question | Answer |
Intrinsic regulating | contraction stimulated w/o nervous system |
sinoatrial node (SA node) | "pace maker" In wall of right atria. Initiate heartbeat. Specialized conducting cells. 72 times/minute |
Atrioventricular Node (AV Node) | In Right atria. Receive from SA node. Pass to AV bundle |
Atrioventricular bundle of His (AV Bundle) | tract of conduction fibers within intervertebral septum. Passes message to purkinje fibers |
Purkinje Fibers | In walls of ventricles. Conduct impulse to myocardium = Ventricular contraction |
Extrinsic regulating | ANS stimulation |
Sympathetic stimulation | increase rate and strength . release norepinephrine. Act on SA Node |
Parasympathetic stimulation | decrease rate and strength, release acetylcholine. Inhibitory |
cardiac cycle | complete heartbeat |
Atria contract | AV valves open, blood rushes into ventricles |
Systole | Ventricles contract, AV valves close, semilunar valves open, blood ejected out. Blood under highest pressure |
Diastole | ventricles relax, semilar lunar valves close, AV valves open, Blood is in atria. Wait for SA node to fire to begin next cycle. Lowest pressure |
Amount of blood pumped every minute | 5L |
Austcultation | listening to body sounds. |
1st heart sound | lubb - AV valves close |
2nd heart sound | dupp - semilunar valves close |
Auscultory areas | adjacent to anatomical location so sternum does not obscure the sound. Listen towards the flow of blood. |
Aortic area | 2nd intercostal space on right side - aortic semilunar valve |
Pulmonic area | 2nd intercostal space on left side. Pulmonic semilunar valve |
Tricuspid area | 5th intercostal space right of sternum. Right AV Valve |
Bicuspid area | 5th intercostal space left of sternum. Near apex. Mitral(left AV valve) |
coronary circulation | supplies heart with blood, carries away waste ... first branches of aorta |
right coronary artery | posterior interventricular. lateral right heart. In septum on posterior side of ventricles |
left coronary artery | anterior interventricular. Interventricular septum(think bundle of His) & anterior walls of ventricles. Cirumflex supply left atrium and posterior left ventricle |
Coronary sinus | blood drained from coronary veins into.. then into right atrium |
Myocardial infarction (MI) | heart attack. Blood clot blocks coronary vessel |
Thrombus | fixed clot |
embolus | moving clot |
Atherosclerosis | fatty deposits in walls = plaque consequence = buildup and blockage |