Geniohyoideus

The Geniohyoideus is a slender muscle in the anterior region of the neck, playing a crucial role in the physiology of swallowing and speech. It is one of the suprahyoid muscles, which are a group of muscles that function to elevate the hyoid bone and help in the opening of the mouth.

Anatomy

The Geniohyoideus originates from the mental spine on the inner surface of the mandible, near the symphysis menti, and inserts into the anterior surface of the body of the hyoid bone. It lies superior to the mylohyoid muscle, another important muscle in the floor of the mouth, and is covered by the mucous membrane of the mouth floor.

Function

The primary function of the Geniohyoideus is to pull the hyoid bone anteriorly and superiorly. This action is important during swallowing and speech, as it helps to widen the pharynx and elevate the larynx. By doing so, it facilitates the passage of food through the pharynx and into the esophagus, and contributes to the modulation of sound. Additionally, when the mandible is fixed, the Geniohyoideus can help in depressing the mandible, contributing to the opening of the mouth.

Innervation

The Geniohyoideus is innervated by the C1 nerve through the hypoglossal nerve. This is unique as most of the other suprahyoid muscles are innervated by the facial nerve or branches of the trigeminal nerve.

Clinical Significance

Dysfunction or damage to the Geniohyoideus can impact swallowing and speech. Conditions such as stroke, neuromuscular diseases, and trauma to the neck can affect the function of this muscle, leading to difficulties in these areas. Rehabilitation exercises targeting the Geniohyoideus and other muscles of the neck can be beneficial in restoring function.

See Also

• Hyoid bone
• Suprahyoid muscles
• Swallowing
• Speech production