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.
In general, the atrioventricular node is located in the so-called floor of the right atrium, over the muscular part of the interventricular septum, inferior to the membranous septum: i.e., within the triangle of Koch, which is bordered by the coronary sinus, the tricuspid valve annulus along the septal leaflet, and the tendon of Todaro (Figure 2).