The space between the parietal and visceral layers of the pericardium that contains serous fluid, secreted by the pericardial membranes, that reduces friction between them when the heart moves within them
Layer of the heart wall that is a serous membrane covered with epithelium that forms a protective outer covering and secretes serous fluid.
Epicardium (Visceral Pericardium)
Layer of the heart wall that is cardiac muscle tissue separated by connective tissue that contracts to pump blood out of the heart chambers.
Layer of the heart wall that is a membrane of epithelium and underlying connective tissue that forms a protective inner lining of the chambers and valves.
List the 3 layers of the wall of the heart from the outside in.
1) Epicardium 2) Myocardium 3) Endocardium
The upper chambers of the heart that have thin walls and receive blood returning to the heart.
Small, earlike projections that extend anteriorly from the atria, slightly increasing atrial volume.
The lower chambers of the heart that force the blood out of the heart into arteries.
List the four chambers of the heart.
The upper left and right atria, and the lower left and right ventricles
List the two receiving (passive) chambers of the heart.
List the two pumping (active) chambers of the heart.
Why are the atria considered "passive" and the ventricles considered "active?"
The ventricles must force blood to move against a resistance to flow, the atria do not
The structure that separates the right from the left atrium.
The structure that separates the two ventricles.
An opening through which the atrium on each side communicates with its corresponding ventricle.
This guards the atrioventricular orifice.
Atrioventricular Valve (AV Valve)
Deepest groove on the surface of the heart which encircles the heart between the atria and ventricles; it marks the division between these chambers and contains major blood vessels that supply the heart tissues.
Two of these (anterior and posterior) mark the septum that separates the right and left ventricles.
This valve guards the atrioventricular orifice between the right atrium and right ventricle; it permits the blood to move from the right atrium into the right ventricle and prevents it from moving in the opposite direction.
Strong, fibrous strings that attach to the cusps of the tricuspid valve on the ventricular side; they originate from the papillary muscles, which pull on these strings as the tricuspid valve closes to prevent the cusps from swinging back into the right atrium.
Small mounds of cardiac muscle tissue that project inward from the walls of the ventricle; they contract when the right ventricle contracts, and as the tricuspid valve closes, they pull on the chordae tendinae and prevent the cusps from swinging back into the right atrium.
This valve prevents blood from moving from the pulmonary trunk into the right ventricle during ventricular relaxation.
Pulmonary (Semilunar) Valve
This valve prevents blood from moving from the left ventricle into the left atrium during ventricular contraction.
Mitral (Bicuspid) Valve
This valve prevents blood from moving from the aorta into the left ventricle during ventricular relaxation.
Aortic (Semilunar) Valve
List the four valves of the heart and where they are located.
To prevent the cusps of the tricuspid valve from swinging back into the right atrium, and to prevent the cusps of the mitral valve from swinging back into the left atrium during ventricular contraction
What valves are also known as AV Valves because of their location between the atria and the ventricles?
Tricuspid and Mitral Valves
What valves are also known as semilunar valves because of their shape?