An intercostal muscle that aids in forced expiration (quiet expiration is a passive process). [ ]

Synonyms: intercostales internus

This is just here as a test because I lose it

Term information



depicted by

has related synonym

intercostal muscle internal layer

homology notes

Behind the thorax, the lateral group (of muscles in reptiles and mammals) remains essentially as for amphibians. (It breaks into three sheet-like layers: external oblique muscle, the internal oblique, and the transversus). More anteriorly, however, the ribs, now enlarged, penetrate and alter this group of muscles. The transversus is excluded from the thorax and the external and internal obliques become, respectively, the external and internal intercostal muscles, which contribute to the new function of ventilation of the lungs.[well established][VHOG]



structure notes

The internal intercostals are responsible for the depression of the ribs decreasing the transverse dimensions of the thoracic cavity. the innermost intercostal muscle, the deep layers of the internal intercostal muscles which are separated from them by the neurovascular bundle. Both the external and internal muscles are innervated by the intercostal nerves, and are provided by the intercostal arteries and intercostal veins. Their fibers run in opposite directions