Exercise 7.1 Part 1: Internal Anatomy of the Heart

myocardium

made up of cardiac muscle tissue; thickest part of the heart

endocardium

inner serous membrane lining the interior of the heart

epicardium

a.k.a. visceral pericardium; outer serous membrane covering the heart

parietal pericardium

external to the epicardium; the double-layered membrane composed of an inner serous membrane and an outer fibrous membrane

pericardial cavity

space between the epicardium and parietal pericardium

atria

upper, thin-walled chambers of the heart which receive blood returning to the heart

ventricles

lower, thick-walled chambers which pump blood into the arteries leaving the heart

ventricular septum

separates the right and left ventricles

tricuspid valve

atrioventricular valve with three flaps, or cusps; occurs between the right atrium and ventricle

mitral valve

bicuspid; atrioventricular valve with two flaps, or cusps; occurs between the left atrium and ventricle

ventricular systole

contraction of the ventricles

ventricular diastole

relaxation of the ventricles

chordae tendineae

sometimes called the heart strings, are cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart

papillary muscles

located on the walls of the ventricles; prevents the valve cusps from being forced into the atria during contraction

pulmonic semilunar valve

located at the base of the pulmonary trunk; prevents the back flow of blood from the arteries into the right ventricle

aortic semilunar valve

located at the base of the aorta; prevents the back flow of blood from the arteries into the left ventricle