The diaphragm is a dome shaped sheet that separates the thoracic and abdominal cavities. It is composed of both muscle and tendon with tendon at the peak of the dome.

Origin

Attaches to the . process, the inner surface of the lower six costal cartilages and to the L1 through the L3 lumbar vertebrae

Insertion

Attaches to the central aponeurotic tendon.

Function

In the respiratory system, the diaphragm is an inspiratory muscle.

Most often the respiratory system, more specifically, the inspiratory and expiratory muscles, are not thought to be trainable except through aerobic type activities.
This, however, is only partially true. The respiratory system muscles can also be strengthened with specific strength training exercises.

Volume 12 - The Respiratory System of our Kinesiology of Exercise Ebooks is a first for a book on strength training for the respiratory system.