The partition dividing the heart into a left and right side is called the _____________.

The partition dividing the heart into a left side and a right side is known as the septum. This muscular wall separates the left atrium and ventricle from the right atrium and ventricle, ensuring that oxygenated and deoxygenated blood do not mix. The septum plays a crucial role in maintaining the efficiency of the heart's function by directing blood flow appropriately through the heart and into the circulation.

The atrium refers to the upper chambers of the heart where blood is collected, while the ventricle refers to the lower chambers responsible for pumping blood out of the heart. Valves are structures that ensure one-way blood flow within the heart but do not serve to divide it into halves. Understanding the function and anatomy of these components highlights the importance of the septum in the heart's structure and function.