Genioglossus

File:Genioglossus.png

Diagram of the genioglossus muscle

The genioglossus is a muscle of the tongue that plays a crucial role in the movement and function of the tongue. It is one of the extrinsic muscles of the tongue, meaning it originates outside the tongue but acts upon it. The genioglossus is responsible for the protrusion and depression of the tongue, which are essential for speech, swallowing, and maintaining an open airway during breathing.

Anatomy

The genioglossus muscle originates from the superior mental spine, a bony projection on the inner surface of the mandible (lower jawbone). From its origin, the muscle fibers fan out posteriorly and superiorly to insert into the entire length of the dorsum of the tongue and the body of the hyoid bone.

File:Slide1ww.JPG

Muscle fibers of the genioglossus

The muscle is innervated by the hypoglossal nerve (cranial nerve XII), which controls the movements of the tongue. The blood supply to the genioglossus is primarily from the lingual artery, a branch of the external carotid artery.

Function

The genioglossus muscle is primarily responsible for the protrusion of the tongue. When the muscle contracts, it pulls the tongue forward and downward, which is essential for various functions such as:

• Speech: The movement of the tongue is crucial for articulating sounds and forming words.
• Swallowing: The genioglossus helps in moving the bolus of food towards the pharynx.
• Airway maintenance: During sleep, the genioglossus helps keep the airway open by preventing the tongue from falling back and obstructing the airway, which is particularly important in preventing obstructive sleep apnea.

Clinical Significance

Dysfunction of the genioglossus muscle can lead to difficulties in speech and swallowing. It can also contribute to sleep-related breathing disorders such as obstructive sleep apnea, where the tongue falls back and obstructs the airway during sleep. Strengthening exercises for the genioglossus are sometimes recommended as part of the treatment for sleep apnea.

Related Pages

• Tongue
• Hypoglossal nerve
• Obstructive sleep apnea
• Lingual artery