Geniohyoid muscle
Encyclopedia
The Geniohyoid muscle is a narrow muscle
situated superior to the medial border of the mylohyoid muscle
. It is named for its passage from the chin
("genio-" is a standard prefix for "chin") to the hyoid bone
.
, on the back of the symphysis menti
, and runs backward and slightly downward, to be inserted into the anterior surface of the body of the hyoid bone
; it lies in contact with its fellow of the opposite side. It thus belongs to the suprahyoid muscles
. The nerve supply to geniohyoid is from C1 running with the hypoglossal nerve
.
of hyoid bone and Genioglossus
occur.
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
situated superior to the medial border of the mylohyoid muscle
Mylohyoid muscle
The mylohyoid muscle is a muscle running from the mandible to the hyoid bone, forming the floor of the oral cavity. It is named for its two attachments, with the prefix "mylo" coming from the Greek word for "molar". These muscles are mesodermal in origin...
. It is named for its passage from the chin
Chin
In the human anatomy, the chin is the lowermost part of the face.It is formed by the lower front of the mandible.People show a wide variety of chin structures. See Cleft chin....
("genio-" is a standard prefix for "chin") to the hyoid bone
Hyoid bone
The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
.
Origin and insertion
It arises from the inferior mental spineMental spine
A mental spine is a small projection of bone on the posterior aspect of the mandible in the midline. There are usually 4 mental spines: 2 superior and 2 inferior. Collectively they are also known as the genial tubercle, genial apophysis and the Latin name spinae mentalis...
, on the back of the symphysis menti
Symphysis menti
The external surface of the mandible is marked in the median line by a faint ridge, indicating the symphysis menti, mandibular symphysis, or line of junction of the two pieces of which the bone is composed at an early period of life....
, and runs backward and slightly downward, to be inserted into the anterior surface of the body of the hyoid bone
Hyoid bone
The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
; it lies in contact with its fellow of the opposite side. It thus belongs to the suprahyoid muscles
Suprahyoid muscles
The term suprahyoid refers to the region above the hyoid bone in the neck. The suprahyoid muscles include digastric, stylohyoid, geniohyoid, and mylohyoid...
. The nerve supply to geniohyoid is from C1 running with the hypoglossal nerve
Hypoglossal nerve
The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal...
.
Action
During the first act of deglutition, when the mass of food is being driven from the mouth into the pharynx, the hyoid bone, and with it the tongue, is carried upward and forward by the anterior bellies of the Digastrici, the Mylohyoidei, and Geniohyoidei. It also assists in depressing the mandibleVariations
It may be blended with the one on opposite side or double; slips to greater cornuGreater cornu
The greater cornua of the hyoid bone project backward from the lateral borders of the body; they are flattened from above downward and diminish in size from before backward; each ends in a tubercle to which is fixed the lateral hyothyroid ligament.The upper surface is rough close to its lateral...
of hyoid bone and Genioglossus
Genioglossus
The genioglossus is a muscle of the human body which runs from the chin to the tongue. The genioglossus is the major muscle responsible for protruding the tongue.-Structure:...
occur.