Vertical muscle of the tongue
The vertical muscle of the tongue is one of the four intrinsic muscles of the tongue which alters the shape of the tongue mass, being entirely confined to the tongue without an extraglossal attachment (cf. extrinsic muscles of the tongue).
Gross anatomy
The muscles fibers attach proximally to the submucosal fibrous layer of the dorsum of the tongue and attach distally to the inferior surface of the apex and lateral tongue margins. They intersect with the fibers of the transverse intrinsic muscle lying between the superior and inferior longitudinal intrinsic muscles.
Innervation
Like all the intrinsic muscles of the tongue, it is innervated by the hypoglossal nerve (CN XII).
Action
The fibers act to flatten and broaden the tongue.