Occipitofrontalis | |
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Details | |
Origin | Two occipital bellies and two frontal bellies. |
Insertion | Epicranial aponeurosis |
Artery | Frontal belly: supraorbital and supratrochlear arteries Occipital belly: occipital artery |
Nerve | Facial nerve |
Actions | Raises eyebrows, wrinkles forehead |
Identifiers | |
Latin | musculus occipitofrontalis or musculus epicranii venter frontalis |
TA98 | A04.1.03.003 |
TA2 | 2055 |
FMA | 9624 |
Anatomical terms of muscle |
The occipitofrontalis muscle (epicranius muscle) is a muscle which covers parts of the skull. It consists of two parts or bellies: the occipital belly, near the occipital bone, and the frontal belly, near the frontal bone. It is supplied by the supraorbital artery, the supratrochlear artery, and the occipital artery. It is innervated by the facial nerve. In humans, the occipitofrontalis helps to create facial expressions.
The occipitofrontalis muscle consists of two parts or bellies:
Some sources consider the occipital and frontal bellies to be two distinct muscles. However, Terminologia Anatomica currently classifies it as a single muscle, and also includes the temporoparietalis muscle as part of the epicranius.
The occipitofrontalis muscle receives blood from several arteries. The frontal belly receives blood from the supraorbital and supratrochlear arteries, while the occipital belly receives blood from the occipital artery. [3]
The occipitofrontalis muscle is innervated by the facial nerve. [4] Branches of the supraorbital nerve pass through the occipitofrontalis muscle without innervating it to innervate the lambdoid suture. [5]
The occipitofrontalis muscle helps to create facial expressions. [6] Assisted by the occipital belly, the frontal belly draws the scalp back, which raises the eyebrows and wrinkles the forehead. [4] [2]
Damage to the facial nerve can cause atony of the occipitofrontalis muscle. [7]
In humans, the occipitofrontalis only serves for facial expressions. In apes, however, the head is not balanced on the vertebral column, and apes therefore need strong muscles that pull back on the skull and prominent supraorbital ridges for the attachment of these muscles. [6]
In human anatomy, the forehead is an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp grows. The bottom of the forehead is marked by the supraorbital ridge, the bone feature of the skull above the eyes. The two sides of the forehead are marked by the temporal ridge, a bone feature that links the supraorbital ridge to the coronal suture line and beyond. However, the eyebrows do not form part of the forehead.
The supraorbital nerve is one of two branches of the frontal nerve, itself a branch of the ophthalmic nerve. The other branch of the frontal nerve is the supratrochlear nerve.
The scalp is the area of the head where head hair grows. It is made up of skin, layers of connective and fibrous tissues, and the membrane of the skull. Anatomically, the scalp is part of the epicranium, a collection of structures covering the cranium. The scalp is bordered by the face at the front, and by the neck at the sides and back. The scientific study of hair and scalp is called trichology.
The omohyoid muscle is a muscle in the neck. It is one of the infrahyoid muscles. It consists of two bellies separated by an intermediate tendon. Its inferior belly is attached to the scapula; its superior belly is attached to the hyoid bone. Its intermediate tendon is anchored to the clavicle and first rib by a fascial sling. The omohyoid is innervated by the ansa cervicalis of the cervical plexus. It acts to depress the hyoid bone.
The digastric muscle is a bilaterally paired suprahyoid muscle located under the jaw. Its posterior belly is attached to the mastoid notch of temporal bone, and its anterior belly is attached to the digastric fossa of mandible; the two bellies are united by an intermediate tendon which is held in a loop that attaches to the hyoid bone. The anterior belly is innervated via the mandibular nerve, and the posterior belly is innervated via the facial nerve. It may act to depress the mandible or elevate the hyoid bone.
The ophthalmic artery (OA) is an artery of the head. It is the first branch of the internal carotid artery distal to the cavernous sinus. Branches of the ophthalmic artery supply all the structures in the orbit around the eye, as well as some structures in the nose, face, and meninges. Occlusion of the ophthalmic artery or its branches can produce sight-threatening conditions.
The corrugator supercilii muscle is a small, narrow, pyramidal muscle of the face. It arises from the medial end of the superciliary arch; it inserts into the deep surface of the skin of the eyebrow.
The stylohyoid muscle is one of the suprahyoid muscles. Its originates from the styloid process of the temporal bone; it inserts onto hyoid bone. It is innervated by a branch of the facial nerve. It acts draw the hyoid bone upwards and backwards.
The frontalis muscle is a muscle which covers parts of the forehead of the skull. Some sources consider the frontalis muscle to be a distinct muscle. However, Terminologia Anatomica currently classifies it as part of the occipitofrontalis muscle along with the occipitalis muscle.
The occipitalis muscle is a muscle which covers parts of the skull. Some sources consider the occipital muscle to be a distinct muscle. However, Terminologia Anatomica currently classifies it as part of the occipitofrontalis muscle along with the frontalis muscle.
The epicranium is the medical term for the collection of structures covering the cranium. It consists of the muscles, aponeurosis, and skin.
The thyrohyoid muscle is a small skeletal muscle of the neck. Above, it attaches onto the greater cornu of the hyoid bone; below, it attaches onto the oblique line of the thyroid cartilage. It is innervated by fibres derived from the cervical spinal nerve 1 that run with the hypoglossal nerve to reach this muscle. The thyrohyoid muscle depresses the hyoid bone and elevates the larynx during swallowing. By controlling the position and shape of the larynx, it aids in making sound.
The supratrochlear nerve is a branch of the frontal nerve, itself a branch of the ophthalmic nerve (CN V1) from the trigeminal nerve (CN V). It provides sensory innervation to the skin of the forehead and the upper eyelid.
The retromandibular vein is a major vein of the face. It is formed within the parotid gland by the confluence of the maxillary vein, and superficial temporal vein. It descends in the gland and splits into two branches upon emerging from the gland. Its anterior branch then joins the (anterior) facial vein forming the common facial vein, while its posterior branch joins the posterior auricular vein forming the external jugular vein.
The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles and it has openings for blood vessels. From its borders, the mastoid part articulates with two other bones.
The posterior auricular nerve is a nerve of the head. It is a branch of the facial nerve. It communicates with branches from the vagus nerve, the great auricular nerve, and the lesser occipital nerve. Its auricular branch supplies the posterior auricular muscle, the intrinsic muscles of the auricle, and gives sensation to the auricle. Its occipital branch supplies the occipitalis muscle.
The supraorbital artery is a branch of the ophthalmic artery. It passes anteriorly within the orbit to exit the orbit through the supraorbital foramen or notch alongside the supraorbital nerve, splitting into two terminal branches which go on to form anastomoses with arteries of the head.
The supratrochlear artery is one of the terminal branches of the ophthalmic artery. It arises within the orbit. It exits the orbit alongside the supratrochlear nerve. It contributes arterial supply to the skin, muscles and pericranium of the forehead.
The zygomatic branches of the facial nerve (malar branches) are nerves of the face. They run across the zygomatic bone to the lateral angle of the orbit. Here, they supply the orbicularis oculi muscle, and join with filaments from the lacrimal nerve and the zygomaticofacial branch of the maxillary nerve (CN V2).
Scalp reconstruction is a surgical procedure for people with scalp defects. Scalp defects may be partial or full thickness and can be congenital or acquired. Because not all layers of the scalp are elastic and the scalp has a convex shape, the use of primary closure is limited. Sometimes the easiest way of closing the wound may not be the ideal or best way. The choice for a reconstruction depends on multiple factors, such as the defect itself, the patient characteristics and surgeon preference.