Inferior longitudinal muscle of the tongue

The inferior longitudinal muscle of the tongue is one of the four intrinsic muscles of the tongue, which alter the shape of the tongue mass, being entirely confined to the tongue without any extraglossal attachment (cf. extrinsic muscles of the tongue).

Gross anatomy

The muscles fibers attach proximally to the root of the tongue and attach distally to the tongue apex.

They lie inferior to the transverse and vertical intrinsic muscles.

Innervation

Like all the intrinsic muscles of the tongue, it is innervated by the hypoglossal nerve (CN XII).

Action

The muscle's fibers act to curl the apex and lateral sides of the tongue downwards and when acting together with the superior longitudinal muscle of the tongue, they shorten and retract the tongue when it is protruding.