Question | Answer |
Approximately ____ of the heart's mass is to the left of the midline. | two thirds (2/3) |
The ____, the innermost layer of the heart, line's the heart's chambers and is bathed in blood. | endocardium |
The ____ is the thick middle layer of the heart. | myocardium |
The myocardium's cells are unique in that they physically resemble skeletal muscle but that electrical properties similar to ____ muscle. | smooth |
The ____ is a protective sac surrounding the heart. | pericardium |
The pericardium consists of two layers, ____ and ____. | visceral, parietal |
The ____ ____, also called the epicardium, is the inner layer, in contact with the heart muscle itself. | visceral pericardium |
The ____ ____ is the outer, fibrous layer. | parietal pericardium |
The heart contains ____ chambers. | four |
The ____, the two superior chambers, receive incoming blood. | atria |
The ____, the two larger, inferior chambers, pump blood out of the heart. | ventricles |
The heart contains two pairs of valves, the ____ valves and the ____ valves, made of endocardial and connective tissue. | atrioventricular, semilunar |
The right atrioventricular valve is called the ____ valve because it has three leaflets, or cusps. | tricuspid |
The left atrioventricular valve, called the ____ valve, has two leaflets. | mitral |
Specialized fibers called ____ ____ connect the valves' leaflets to the papillary muscles. | chordae tendineae |
The chordae tendineae prevent the valves from prolapsing into the atria and allowing ____ during ventricular contraction. | backflow |
The ____ ____ originate in the aorta, just above the leaflets of the ___ valve. | coronary arteries, aortic |
____ ____ is the period of time from the end of one cardiac contraction to the end of the next. | Cardiac cycle |
____ is the period of time when the myocardium is relaxed and cardiac filling and coronary perfusion occur. | Diastole |
____ is the period of the cardiac cycle when the myocardium is contracting. | Systole |
____ is pertaining to heart rate. | Chronotrophy |
____ is pertaining to cardiac contractile force (B/P). | Inotrophy |
____ is pertaining to the speed of impulse transmission (EKG). | Dromotrophy |
____ ____ are specialized bands of tissue inserted between myocardial cells that increase the rate in which the action potential is spread from cell to cell. | Intercalated discs |
____ is a group of cardiac muscle cells that physiologically function as a unit. | Syncytium |
____ ____ is a reversal of charges at a cell membrane so that the inside of the cell becomes positive in relation to the outside. | Cardiac depolarization |
____ ____ is the opposite of the cell's resting state in which the inside of the cell is negative in relation to the outside. | Cardiac depolarization |
____ ____ is the normal electrical state of cardiac cells. | Resting potential |
____ ____ is the stimulation of myocardial cells, as evidenced by a change in the electrical charge, that subsequently spreads across the myocardium. | Acting potential |
____ is the ability of the cells to respond to an electrical stimulation. | Excitability |
____ is the ability of the cells to propagate the electrical impulse from one cell to another. | Conductivity |
____ is the pacemaker cells' capability of self depolarization. | Automaticity |
____ is the ability of muscle cells to contact, or shorten. | Contractility |
SA node = ____-____ beats per minute | 60-100 |
AV node = ____-____ beats per minute | 40-60 |
Purkinje system = ____-____ beats per minute | 15-40 |