The ___________ is a strong wall of muscle that contracts to create a suction in the chest to draw in air and expand the lungs. When the muscle relaxes, the chest cavity decreases and the air is pushed out.
The diaphragm is a strong wall of muscle that contracts to create a suction in the chest to draw in air and expand the lungs. When the muscle relaxes, the chest cavity decreases and the air is pushed out.
