Costal part of diaphragm

The costal part of the diaphragm is one of the three main segments of the diaphragm (others are the sternal and lumbar parts).

The costal part originates from the inner surfaces of the lower six ribs and their costal cartilages and inserts into the central tendon of the diaphragm (a strong aponeurotic structure that serves as the insertion point for all diaphragmatic muscle fibers).

The costal fibers of the diaphragm are arranged in a radial pattern, converging towards the central tendon. These fibers are responsible for the primary movement of the diaphragm during respiration, facilitating the expansion and contraction of the thoracic cavity. The costal part of the diaphragm is also involved in maintaining the pressure gradient between the thoracic and abdominal cavities.