The large sheet of muscle that divides the chest (thorax) from the abdomen and provides most of the power that moves air in and out of the lungs. The diaphragm is attached to the spine, ribs, and sternum, forming the floor of the chest cavity. In a resting position, the diaphragm curves up into the chest cavity. During inhalation, the diaphragm contracts, flattening and moving downward as much as 3 to 4 inches. This change in the shape of the chest lowers its internal pressure and draws air into the lungs. During exhalation, the diaphragm relaxes and rises into its former position, while pressure in the lungs increases, and air is forced out of the lungs. Contraction and relaxation of the muscles between the ribs add to the diaphragm’s action.
A vital anatomical structure, the diaphragm, assumes the form of a dome-shaped muscular sheet that separates the chest cavity from the abdominal region. This remarkable muscle attaches to the spine, ribs, and sternum, also known as the breastbone. Its remarkable design incorporates specialized openings for the passage of the esophagus, major nerves, and blood vessels, ensuring seamless communication and circulation within the body.
The diaphragm assumes a pivotal role in the process of respiration. It performs a remarkable function during inhalation by contracting its muscle fibers, resulting in a downward movement that facilitates the entry of air into the lungs. Conversely, during exhalation, the diaphragm muscle relaxes, causing it to ascend, thereby enabling the expulsion of air from the lungs. This intricate interplay of muscular action ensures the vital exchange of oxygen and carbon dioxide within the respiratory system.