Breathing is the exchange of air through the involved passages in between the atmosphere and the lungs. Inspiration is a process where we take air into the lungs from the atmosphere also known as inhalation.
Expiration is releasing air out of the lungs to the atmosphere. In expiration, the diaphragm relaxation and elastic recoil of tissue decrease the thoracic volume of lungs. That results in an increase the intraalveolar pressure in the lungs.
