According to faculty of Springfield Technical Community College, inspiration and expiration are processes that get air into and out of the body. Both processes involve the human respiratory system.
LifeEasy Biology defines inspiration as the process of inhalation or the intake of air. Oxygen enters the body by way of inspiration. It takes place by the contraction of the diaphragm and internal and external intercostal muscles. The process of inspiration is an active process.
When explaining inspiration, faculty of Springfield Technical Community College states that humans have a clear passageway for air, from outside into the nasal cavity, to the pharynx, trachea, bronchi, bronchioles and alveoli. Humans must get air into the alveoli because that's where gas exchange occurs.
LifeEasy Biology defines expiration as the process of exhalation or breathing out air. Carbon dioxide exits the body by way of expiration. It takes place by elastic recall of the diaphragm and the relaxation of intercostal muscles. The process of expiration is a passive process.
Faculty of Springfield Technical Community College explains that exhaling passively means that humans do not have to expend any energy to exhale. Once the diaphragm has stopped contracting for inspiration, it can then begin to relax for exhalation.