The part of the respiratory system that is composed of skeletal muscle is the diaphragm. It is a part of the said system which is made up skeletal muscles which functions for ventilation. It has a shape of a dome that acts the primary muscle for respiration and has an essential role in breathing. It goes through contraction and relaxation which alters the volume of the cavity and the lungs. It separates the chest from the abdomen. It consists of two portions namely the peripheral muscle and the central tendon. There are three pathways for this part namely the Oesophageal opening, Aortic opening and Caval opening.