Term | Definition |
aorta | the largest artery of the body |
atrium | one of the two upper chambers of the heart that receive venous blood from the lungs or the body |
cardiac cycle | the sequence of events in one heartbeat, in which simultaneous contraction of the atria is followed by simultaneous contraction of the ventricles |
cardiac output | the amount of blood pumped by a ventricle in one minute |
coronary arteries | the blood vessels that circulate blood throughout the myocardium |
diastole | in the cardiac cycle, the relaxation of the myocardium |
endocardium | the simple squamous epithelial tissue that lines the chambers of the heart and covers the valves |
epicardium | the serous membrane on the surface of the myocardium |
mediastinum | the area or space between the lungs |
mitral valve | the left atrioventricular valve, which prevents backflow of blood from the left ventricle to the left atrium when the ventricle contracts |
myocardium | the cardiac muscle tissue that forms the walls of the chambers of the heart |
sinoatrial node | the first part of the atrial conduction pathway, located in the wall of the right atrium |
stroke volume | the amount of blood pumped by a ventricle in one beat |
systole | in the cardiac cycle, the contraction of the myocardium |
tricuspid valve | the right AV valve, which prevents backflow of blood from the right ventricle to the right atrium when the ventricle contracts |
venous return | the amount of blood returned by the veins to the heart |
ventricle | one of the two lower chambers of the heart that pump blood to the body or to the lungs |
arrhythmia | an abnormal or irregular rhythm of the heart |
ectopic focus | the initiation of a heartbeat by part of the myocardium other than the sinoatrial node |
ejection fraction | the percent of blood in a ventricle that is pumped during systole |
electrocardiogram | a recording of the electrical changes that accompany the cardiac cycle |
filibration | very rapid and uncoordinated heartbeats |
heart murmur | an abnormal heart sound heard during the cardiac cycle |
ischemic | lack of blood to a body part, often due to an obstruction of circulation |
myocardial infarction | death of part of the heart muscle due to lack of oxygen |
pulse | the force of the heartbeat detected at an arterial site such as the radial artery |
stenosis | an abnormal constriction or narrowing of an opening or a duct |