Muscles of respiration

Muscles of respiration are those muscles of the body, which help lungs in the process of exchange of gases.


It is the primary muscle of respiration. For more details, click here

Levatores costarum muscle:

These are 12 pairs of muscles each arising from the tip of the transverse process of a thoracic vertebra and inserted into the rib below. Each muscle is triangular in shape with its apex lying towards the origin.

Action: Each muscle raises the rib below and is therefore and inspiratroy muscle.

Nerve supply: Each muscle is supplied by posterior ramus of corresponding thoracic spinal nerve.

Serratus posterior superior muscle:

It is a thin flat muscle that arises from the lower cervical and upper thoracic spines. Its fibers pass downward and laterally to be inserted into the upper ribs.

Action: Serratus posterior superior muscle elevates the ribs on its contraction and is therefore a inspiratory muscle.

Nerve supply: It is innervated by the intercostal nerves.

Serratus posterior inferior muscle:

It is also a flat muscle that arises from the lower thoracic and upper lumbar spines. It passes upward and laterally to be inserted into lower ribs.

Action: On its contraction, it depresses the ribs and is therefore an exspiratory muscle.

Nerve supply: It is also innervated by intercostal nerves.