Squamous cell carcinoma of the tongue -exophytic mass (2 of 3)

The dorsal aspect of the tongue may be thought of as divided into thirds. The anterior two thirds is known as the oral tongue, and it is this portion that is mobile. The oral tongue is demarcated from the posterior one third, or base of the tongue by the circumvallate papillae. Just posterior to these papillae is the sulcus terminalis, the embryologic dividing line between the structures of the first branchial arch (the oral tongue) and those deriving from the second, third and fourth branchial arches (the tongue base) The oral tongue is closely related anatomically to the tonsillar pillars posterolaterally, and the floor of the mouth inferiorly. The tongue is a muscular organ, composed of both extrinsic and intrinsic muscles. The extrinsic muscles serve primarily to change the position of the tongue and thus attach outside of the lingual body. The intrinsic muscles do not attach outside of the tongue and serve to change the shape of the lingual surface.