The inferior longitudinal muscles of the tongue form a band like structure on either side near to its inferior surface. They originate from the fibrous tissue beneath the mucous membrane stretching from tip of tongue longitudinally back to the root of the tongue and the hyoid bone. They insert into the mucous membrane of the tongue dorsum.
The inferior longitudinal muscles act to curl the tip of the tongue inferiorly. This makes the dorsum of the tongue convex in shape.