What does the interventricular septum separate?

The interventricular septum is a strong muscular wall that separates the left and right ventricles of the heart. This structure is crucial for maintaining the separation of oxygenated blood in the left ventricle from deoxygenated blood in the right ventricle, thereby ensuring efficient blood circulation throughout the body.

The ventricles are responsible for pumping blood: the left ventricle pumps oxygen-rich blood to the body, whereas the right ventricle pumps oxygen-poor blood to the lungs. If there were a defect in the interventricular septum, such as a hole, it could lead to mixed blood flow between the two ventricles, which would impair the heart's function and compromise systemic oxygen delivery.

This functional and structural importance of the interventricular septum emphasizes its role specifically in separating the ventricles rather than any other cardiac structures, such as valves or atria, which have distinct functions and anatomical boundaries.