MUSCLE PHYSIOLOGY

Detailed explanation-1: -Contraction of the diaphragm expands the abdomen and the lower part of the rib cage (abdominal rib cage). The rib cage muscles, including the intercostals, the parasternals, the scalene and the neck muscles, mostly act on the upper part of the rib cage (pulmonary rib cage) and are both inspiratory and expiratory.

Detailed explanation-2: -In regular respiration, the genioglossus and other muscles of the floor of the mouth, such as the hypoglossus, are electrically involved in coordination with the diaphragm, immediately before contraction of the diaphragm itself.

Detailed explanation-3: -The intercostal muscles and neck muscles help move the rib cage and thus assist in breathing. Abdominal muscles are sometimes involved in breathing out. The process of breathing out (called exhalation or expiration) is usually passive when a person is not exercising.

Detailed explanation-4: -The diaphragm, a dome-shaped sheet of muscle that separates the chest cavity from the abdomen, is the most important muscle used for breathing in (called inhalation or inspiration). The diaphragm is attached to the base of the sternum, the lower parts of the rib cage, and the spine.