Parts of Respiration

Parts of Respiration

Physiology of diaphragm

Diaphragm is present in thoracic cavity and below the lungs. Diaphragm is dome shaped structure. Diaphragm process complete in two steps:

1. Inspiration
2. Expiration 

Inspiration

During inhalation of air, Diaphragm is contract and becomes flat which increase transverse diameters of thoracic cavity. Process of inhalation, external intercostals muscles are contracts, rib-cage outwards and upwards which increase the anterior posterior diameter of the thoracic cavity and increase thoracic volume. Rushing of oxygenated air into lungs.

Expiration

During exhalation or expel out air from body, diaphragm get relaxes and becomes dome shaped. External coastal muscles are relax, rib-cage downward and inward which decrease the anterior posterior diameter and decrease in thoracic volume.