what do expiratory muscles do?
–Abdominal muscles are active throughout breathing to support the respiratory system.
•Provide maximal advantage for movement of the rib cage, so expiration of the rib cage does not cause expansion of the abdomen (which would reduce the force of rib cage expiration).
•Abdominal muscles contract at rest to held place the diaphragm at its physiologic rest length.
–The length at which the diaphragm can contract most quickly and most strongly.
–Contract during expiration to generate pressure for speech.
•Without inspiratory muscles, what can a person not do?
•Without expiratory muscles, what can a person not do?