The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste, as much of the upper surface of the tongue is covered in papillae and taste buds.

It is sensitive and kept moist by saliva, and is richly supplied with nerves and blood vessels. In humans a secondary function of the tongue is phonetic articulation. The tongue also serves as a natural means of cleaning one’s teeth.

Musculature

The eight muscles of the human tongue are classified as either intrinsic or extrinsic. The four intrinsic muscles act to change the shape of the tongue, and are not attached to any bone. The four extrinsic muscles act to change the position the tongue, and are anchored to bone.

Vasculature
The underside of a human tongue

The tongue receives its blood supply primarily from the lingual artery, a branch of the external carotid artery. The floor of the mouth also receives its blood supply from the lingual artery. The triangle formed by the intermediate tendon of the digastric muscle, the posterior border of the mylohyoid muscle, and the hypoglossal nerve is sometimes called Pirogov’s, Pirogoff’s, or Pirogov-Belclard’s triangle.

The lingual artery is a good place to stop severe hemorrage from the tongue. There is also secondary blood supply to the tongue from the tonsillar branch of the facial artery and the ascending pharyngeal artery.

Nerve supply
Taste for the anterior 2/3 of the tongue is supplied by the Facial nerve (Chorda tympani, CN7). General sensation of the anterior 2/3 is supplied by the Lingual nerve which is a branch of V3 of the Trigeminal nerve CN V.
Taste as well as general sensation for the posterior 1/3 is supplied by the Glossopharyngeal nerve (CN 9).
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