The frontalis muscle () is a

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

which covers parts of the

forehead 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 fo ...

of the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. Some sources consider the frontalis muscle to be a distinct muscle. However,

Terminologia Anatomica ''Terminologia Anatomica'' (commonly abbreviated TA) is the international standard for human anatomy, human anatomical terminology. It is developed by the Federative International Programme on Anatomical Terminology (FIPAT) a program of the Inter ...

currently classifies it as part of the

occipitofrontalis 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 ...

along with the

occipitalis muscle The occipitalis muscle (occipital belly) 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 musc ...

. In humans, the frontalis muscle only serves for facial expressions. The frontalis muscle is supplied by the

facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of ta ...

and receives blood from the supraorbital and supratrochlear arteries.

Structure

The frontalis muscle is thin, of a quadrilateral form, and intimately adherent to the

superficial fascia A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location. Th ...

. It is broader than the

occipitalis The occipitalis muscle (occipital belly) 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 musc ...

and its fibers are longer and paler in color. It is located on the front of the head. The muscle has no bony attachments. Its medial fibers are continuous with those of the

procerus The procerus muscle (or pyramidalis nasi) is a small pyramidal muscle in the glabella. It is involved in facial expressions such as frowning and those associated with attentional control, and it indirectly helps shield the eyes from bright light ...

; its intermediate fibers blend with the corrugator and

orbicularis oculi The orbicularis oculi is a sphincter-like muscle in the face that closes the eyelids. It arises from the nasal part of the frontal bone, from the frontal process of the maxilla in front of the lacrimal groove, and from the anterior surface and b ...

muscles, thus attached to the skin of the eyebrows; and its lateral fibers are also blended with the latter muscle over the

zygomatic process The zygomatic processes (aka. malar) are three processes (protrusions) from other bones of the skull which each articulate with the zygomatic bone. The three processes are: * Zygomatic process of frontal bone from the frontal bone * Zygomatic ...

of the

frontal bone In the human skull, the frontal bone or sincipital bone is an unpaired bone which consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bo ...

. From these attachments the fibers are directed upward, and join the

galea aponeurotica The epicranial aponeurosis (aponeurosis epicranialis, galea aponeurotica) is an aponeurosis (a tough layer of dense fibrous tissue). It covers the upper part of the skull in humans and many other animals. Structure In humans, the epicranial ...

below the

coronal suture The coronal suture is a dense, fibrous connective tissue joint that separates the two parietal bones from the frontal bone of the skull. Structure The coronal suture lies between the paired parietal bones and the frontal bone of the skull ...

. The medial margins of the frontalis muscles are joined together for some distance above the root of the

nose A nose is a sensory organ and respiratory structure in vertebrates. It consists of a nasal cavity inside the head, and an external nose on the face. The external nose houses the nostrils, or nares, a pair of tubes providing airflow through the ...

; but between the occipitales there is a considerable, though variable, interval, occupied by the

Function

In humans, the frontalis muscle only serves for facial expressions. In the eyebrows, its primary function is to lift them (thus opposing the orbital portion of the orbicularis), especially when looking up. It also acts when a view is too distant or dim."eye, human."Encyclopædia Britannica. 2008.

Encyclopædia Britannica 2006 Ultimate Reference Suite DVD An encyclopedia is a reference work or compendium providing summaries of knowledge, either general or special, in a particular field or discipline. Encyclopedias are divided into articles or entries that are arranged alphabetically by artic ...

2009 The frontalis muscle also serves to wrinkle the forehead.

Additional images

File:Frontalis muscle animation small.gif, Position of frontalis muscle (shown in red)

References

External links

PTCentral
{{Authority control Muscles of the head and neck Facial muscles Human head and neck

Structure

Function

Additional images

See also

References

External links