The Hyoglossus is a very thin muscle located just below Adam’s apple in the neck and passes upwards to attach to sides of the tongue. The function of the Hyoglossus is to depress and retract the tongue. Without this function singing would be quite difficult.
The Hyoglossus functions well during life and rarely does it get injured. The two disorders which can affect function of this muscle include stab wounds or a stroke.
The Hyoglossus, thin and quadrilateral, arises from the side of the body and from the whole length of the greater cornu of the hyoid bone, and passes almost vertically upward to enter the side of the tongue, between the Styloglossus and Longitudinalis inferior.
The hyoglossus depresses and retracts the tongue makes the dorsum more convex
The fibers arising from the body of the hyoid bone overlap those from the greater cornu.
It is important in singing.
Structures passing medially to the hyoglossus muscle are the lingual vein and lingual artery. Laterally, in between the hyoglossus muscle and the mylohyoid muscle lay several important structures (from superior in inferior): submandibular gland, submandibular duct, lingual nerve, vena comitans of hypoglossal nerve, and the hypoglossal nerve. Note, posteriorly, the lingual nerve is superior to the submandibular duct and a portion of the submandibular salivary gland protrudes into the space between the hyoglossus and mylohyoid muscles.