Which muscle is primarily responsible for the breathing process?

The diaphragm is the primary muscle responsible for the breathing process. It is a dome-shaped muscle located at the base of the thoracic cavity, separating the thorax from the abdomen. When you inhale, the diaphragm contracts and moves downward, expanding the chest cavity. This decrease in internal pressure allows air to flow into the lungs. During exhalation, the diaphragm relaxes and moves back to its original position, pushing air out of the lungs.

While intercostal muscles assist in breathing by elevating and depressing the ribs to further increase or decrease the volume of the thoracic cavity, the diaphragm is the main driver of respiration. The rectus abdominis and serratus anterior muscles do not play a primary role in the act of breathing; the rectus abdominis is more involved in flexing the spine and stabilizing the trunk, while the serratus anterior is primarily associated with the movement of the shoulder. Thus, the diaphragm’s unique structure and function make it essential for the breathing process.