Not only do the muscles of tongue play an important role in deglutition and tasting the food we eat but also in language production, since we use it to pronounce the letters of the alphabet. There are two types of muscles of tongue; extrinsic and intrinsic ones.
The extrinsic muscles are those located at the base of the tongue and they make it possible for us to swallow the food we eat; this is called deglutition. They are anchored to the hyoid bone, the mandible, and the styloid process and they are innervated by the hypoglossal nerve (CNXII) and receive oxygen-rich blood from the lingual artery, which originates from the external carotid artery. On the other hand, the intrinsic muscles constitute the body of the tongue and are involved in speech, whose center is located in the Broca’s area of the brain frontal lobe. They are also innervated by the hypoglossal nerve and supplied by branches of the lingual artery.
Extrinsic muscles
1) Genioglossus: it arises from the symphysis of mandible. Then it fans out as it runs up to insert at the base of tongue and at the hyoid bone. It depresses and protrudes the tongue.
2) Hyoglossus: it originates from the hyoid bone and goes up to insert between the intrinsic muscles of tongue. It draws back and down the tongue.
3) Stylohyoid: it emerges from the styloid process and is inserted into the sides of tongue. It pulls back this organ.
4) Chondroglossus: it originates from lesser horn of hyoid bone, inserting into the hyoglossus fibers.
Intrinsic muscles
1) Superior longitudinal
2) Transverse
3) Vertical
4) Inferior longitudinal
Below, two images of the muscles of tongue; the first one showing the extrinsic and the other the intrinsic muscles.
