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Aantomy&Physiology
Chapter 16&17: Heart and Function of the Heart
Term | Definition |
---|---|
Function of the Heart | the heart pumps blood, keeps blood circulating, circulates O2 and nutrients |
The Heart | located in mediastinum, thoracic cavity, medial to lungs, superior to diaphragm, and has apex and base |
Membranes of the Heart-serous fluid between parietal and viseral-allows movement without friction seous fluid keeps things flowing; myo-middle, endo-inner, epi-outer | 3 layers enclose heart: myocardium-middle layer, thickest, its the most important muscle; endocardium-innermost layer, lines the inside the ventricle; Epicardium-thin,outer (pericardium), Epi/viseral/parietal |
Heart Chambers | 4 chambers of myocardium,endocardium-lines the 4 chambers&covers valves,upper chambers-right/left atria, interatrial septum atria receive venous blood, lower chambers-right/left ventricles,interventricular septum ventricles send(pump) blood into arteries |
Right Atrium | receives blood through superior&inferior vena cava, tricuspid valve prevents backflow |
Left Atrium | receives blood from lungs, through pulmonary veins, mitral valve (left AV or bicuspid) prevents backflow |
Right Ventricle | sends/pumps blood to lungs via pulmonary artery (P.A.), pulmonary semilunar valve, papillary muscles and chordae tendinae |
Left Ventricle | thicker walls than right ventricle, sends/pumps blood to body through aorta, aortic semilunar valve, papillary muscles & chordae tendinae; left is strong then right because it sends blood to the body, valves are one way doors |
Heart-A double Pump | right heart receives deoxgyenated blood from body -> lungs, left heart receives oxgyenated blood from lungs -> to body, both sides work at same time; vena cava brings deoxygenated blood into the heart, pulmonary-lungs |
Cardiac Cycle | two atria contract, then rest, then two ventricles contract, then rest, systole-contract, diastole-relaxation |
Coronary Vessesl-purpose of the coronary vessels is to supply oxygen to the myocardium the point of coronary arteries is to supply the heart muscle with oxygen the point of coronary vessels is supply oxygen | supplies oxygenated blood to myocardium, right&left coronary arteries branch off ascending aorta, smaller arteries, capillaries (gases exchange), coronary veins, coronary sinus |
Myocardial infarction | heart attack, obstruction of a coronary artery, that area of myocardium dies; if one side will die if the other side does not get oxygen |
ANH-you release the ANH to release fluid to decrease blood volume & make blood pressure back to normal | atrial natriuretic hormone-helps you get rid of water, produced by atria when stretched, decreases blood volume & BP to normal, has to do with the brain, makes VS release fluid, when atria becomes stretched |
Heart Sounds | Lub-Dub, first sound-ventricular systole & AV valves close, second sound-aotric & pulmonary semilunar vlaves close, heart murmur-valves do not close properly; cardia cycle creates the heart sounds 1st sound is longest & loudest |
Conduction System | SA node begins heart beat-the pacemaker of the heart: if messed up, you get a pacemaker, AV node-apath bundle of HIS, R & L bundle branches, purkinje fibers |
ECG/EKG | electrocardiogram-heart's electrical activity, P-wave-depolarization of atria, QRS-complex- depolarization of ventricles, T wave- repolarization of ventricles |
ECG/EKG | 60-100 beats per minute-adult, bradycardia: <60 bpm, trachycardia: >100 bpm; brady- slow heart, trachy- fast heart |
Autonomic Control-nervous system in the brain medulla controls heart rate, sympathetic is controlled by the medulla | Sympathetic-SA nodefire-pacemaker of the heart, increases speed of impulse, increases forced by strengthening myocardium; Parasympathetic- vagal tone (vagal nerve), gender, age, exercise, stumulation, hormones, pathology, medications may alter |
Stroke Volume | stroke volume: amount pumped per beat |
Starling's law-think gyser | due to stretch of fibers, greater stretch, stronger the force of contraction...increase in amount of blood entering ventricle causes the stretch and increases the force, increases volume; the more blood in the ventricle, they will contract harder. |
Inotropic effecteyou release the ANH to release fluid to tors | increase stroke volume by strengthening the force of the myocardium, Hormones, drugs are common causes; does not cause a stretch epipen |
Cardia Output | amount of blood pumped, (by ventricle) in one minute; stroke volume is the amount of blood pumped per beat, cardiac output is the amount of blood pumped per minute |
END-Diastolic volume | end-diastolic volume, EDV-amount of blood in ventricle at the end of resting phase; preload, blood in ventricles at the end of diastole; both end-diastolic volume & preload are the same; end-diastolic volume is amount of blood at end of resting phase |
Ejection Fraction | ejection fraction: % of blood in ventricle pumped per beat |
Brain & Heart | medulla controls heart rate, pressorecptors, chemoreceptors |
Term | angioplasty-like a balloon but removed after inflated stent placement-a balloon inflated and kept in bypass surgery-vein graft restores blood flow to coronary arteries |