Corpus: Genioglossus muscle

The genioglossus muscle is a fan-shaped muscle that is part of the external tongue muscles, forming a significant portion of the tongue's muscle mass.

The genioglossus muscle originates from the mental spines of the lower jaw (mandible).

The muscle inserts into the body of the tongue and the tongue’s fibrous structure (aponeurosis). Some fibers also attach to the hyoid bone and the epiglottis.

The genioglossus muscle is innervated by the hypoglossal nerve (cranial nerve XII), which innervates all tongue muscles except the palatoglossus.

The genioglossus muscle functions to protrude and depress the tongue. It plays a crucial role in chewing, swallowing, and speaking, in coordination with other tongue muscles.

In cases of unconsciousness and obstructive sleep apnea syndrome (OSAS), relaxation of the genioglossus muscle can cause the tongue to fall back, potentially leading to airway obstruction.