Inspiration is the process of inhaling air from the nose that reaches the lungs through respiratory tract. Expiration is the release of air from the lungs to the outside environment through the nose.
During inspiration, the ribs move up and out, diaphragm moves up or inferiorly, the external intercoastals contract and the thoracic cavity increases in volume for the air to come in. During expiration, the opposite of inspiration occurs. Both inspiration and expiration are related.
