THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The right atrium and left atrium are separated by a wall of tissue called the atrial septum. The two lower chambers are called the ventricles, and are separated into the right and left ventricle by the ventricular septum.

Detailed explanation-2: -A wall of muscle called the septum separates the left and right atria and the left and right ventricles. These are referred to as the atrial and ventricular septum.

Detailed explanation-3: -…a partition known as the interatrial septum; the lower chambers, the ventricles, are separated by the interventricular septum.

Detailed explanation-4: -The septum separates the atria and ventricles in such a way that it forms a barrier between the heart chambers and this prevents mixing of oxygenated and deoxygenated blood.