exists and is an alternate of . Direct observation means looking at it with your own two eyes, feeling it with your fingers (or other body parts), directly hearing it with your ears or directly tasting it with your tongue. Indirect observation means not sensing the object of observation directly but by observing the effects it has on its surroundings.
The atrioventricular valve between the left atrium and the left ventricle is called the bicuspid valve (also known as the mitral valve), and the atrioventricular valve between the right atrium and the right ventricle is called the tricuspid valve.
The mitral valve along with the tricuspid valve are known collectively as the atrioventricular valves because they lie between the atria and the ventricles of the heart. In normal conditions, blood flows through an open mitral valve during diastole with contraction of the left atrium, and the mitral valve closes during systole with contraction of the left ventricle.