a&p - heart vocabulary

Atrioventricular valve

allow blood to flow one way from atrium to ventricle on same side

Atrium

Right receives blood from systemic circuit; left receives blood from pulmonary circuit

Cardiac cycle

Period between start of one heartbeat and start of the next

Cardiac output

volume of blood ejected from a ventricle in one minute; an indicator of blood flow to the tissues, or perfusion

Diastole

relaxation of a chamber

Electrocardiogram

Electrical events of the heart travel through body; Can be monitored with electrodes for diagnosis of cardiac arrhythmias, abnormal cardiac activity

Endocardium

Covers inside of chambers and heart valves

Epicardium

Covers the outer surface of heart

Intercalated disc

Cells are linked by desmosomes and gap junctions; Increases efficiency during contraction

Myocardium

Contains cardiac muscle cells; Forms bands that wrap and spiral that produces twisting and squeezing during contraction

Pericardium

surrounds the pericardial cavity which surrounds the heart

Purkinje Fibers

Specialized, fast-conducting muscle cells located in the inner ventricular walls of the heart

Sinoatrial node

one of two nodal cells that initiate rate of contraction

Systole

contraction of a chamber

Ventricle

right pumps blood into the pulmonary circuit; left pumps blood into systemic circuit