HOME

TheInfoList



OR:

The facial muscles are a group of striated
skeletal muscle Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are a ...
s 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 ...
(cranial nerve VII) that, among other things, control facial expression. These muscles are also called mimetic muscles. They are only found in
mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
s, although they derive from
neural crest The neural crest is a ridge-like structure that is formed transiently between the epidermal ectoderm and neural plate during vertebrate development. Neural crest cells originate from this structure through the epithelial-mesenchymal transition, ...
cells found in all vertebrates. They are the only muscles that attach to the
dermis The dermis or corium is a layer of skin between the epidermis (skin), epidermis (with which it makes up the cutis (anatomy), cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from s ...
.


Structure

The facial muscles are just under the skin ( subcutaneous) muscles that control facial expression. They generally originate from the surface 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 ...
bone (rarely the fascia), and insert on the skin of the face. When they contract, the skin moves. These muscles also cause wrinkles at right angles to the muscles’ action line.


Nerve supply

The facial muscles are supplied by the facial nerve (cranial nerve VII), with each nerve serving one side of the face. In contrast, the nearby
masticatory muscles The four classical muscles of mastication elevate the mandible (closing the jaw) and move it forward/backward and laterally, facilitating biting and chewing. Other muscles are responsible for opening the jaw, namely the geniohyoid, mylohyoid, and ...
are supplied by the
mandibular nerve In neuroanatomy, the mandibular nerve (V) is the largest of the three divisions of the trigeminal nerve, the fifth Cranial nerves, cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which ...
, a branch of the
trigeminal nerve In neuroanatomy, the trigeminal nerve (literal translation, lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for Sense, sensation in the face and motor functions ...
(cranial nerve V).


List of muscles

The facial muscles include: *
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 ...
*
Temporoparietalis muscle The temporoparietalis muscle is a distinct muscle of the head. It lies above the superior auricular muscle, auricularis superior muscle. It lies just inferior to the epicranial aponeurosis of the occipitofrontalis muscle. The temporoparietalis mu ...
*
Procerus muscle 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 ligh ...
*
Nasalis muscle The nasalis muscle is a sphincter-like muscle of the Human nose, nose. It has a transverse part and an alar part. It compresses the nasal cartilages, and can "flare" the Nostril, nostrils. It can be used to test the facial nerve (VII), which suppl ...
*
Depressor septi nasi muscle The depressor septi nasi muscle (or depressor alae nasi muscle) is a muscle of the face. It connects the incisive fossa of the maxilla and the orbicularis oris muscle to the nasal septum of the nose. It draws the ala of the nose downwards, re ...
*
Orbicularis oculi muscle The orbicularis oculi is a Sphincter, 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 surf ...
*
Corrugator supercilii muscle 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. It draws the eyebrow downward and medially, p ...
* Depressor supercilii muscle *
Auricular muscles The outer ear, external ear, or auris externa is the external part of the ear, which consists of the auricle (also pinna) and the ear canal. It gathers sound energy and focuses it on the eardrum ( tympanic membrane). Structure Auricle The ...
(
anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
,
superior Superior may refer to: *Superior (hierarchy), something which is higher in a hierarchical structure of any kind Places * Superior (proposed U.S. state), an unsuccessful proposal for the Upper Peninsula of Michigan to form a separate state *Lak ...
and posterior) *
Orbicularis oris muscle In human anatomy, the orbicularis oris muscle is a complex of muscles in the lips that encircles the mouth. It is not a true sphincter, as was once thought, as it is actually composed of four independent quadrants that interlace and give only an a ...
*
Depressor anguli oris muscle The depressor anguli oris muscle (triangularis muscle) is a facial muscle. It originates from the mandible and inserts into the angle of the mouth. It is associated with frowning, as it depresses the corner of the mouth. Structure The depres ...
*
Risorius The risorius muscle is a highly variable muscle of facial expression. It has numerous and very variable origins, and inserts into the angle of the mouth. It receives motor innervation from branches of facial nerve (CN VII). It may be absent or a ...
*
Zygomaticus major muscle The zygomaticus major muscle is a muscle of the face. It arises from either zygomatic arch (cheekbone); it inserts at the corner of the mouth. It is innervated by branches of the facial nerve (cranial nerve VII). It is a muscle of facial expres ...
*
Zygomaticus minor muscle The zygomaticus minor muscle is a muscle of facial expression. It originates from the zygomatic bone, lateral to the rest of the levator labii superioris muscle, and inserts into the outer part of the upper lip. It draws the upper lip backward, u ...
*
Levator labii superioris The levator labii superioris (: ''levatores labii superioris'', also called quadratus labii superioris, : ''quadrati labii superioris'') is a muscle of the human body used in facial expression. It is a broad sheet, the origin of which extends fro ...
*
Levator labii superioris alaeque nasi muscle The levator labii superioris alaeque nasi muscle (occasionally shortened alaeque nasi muscle) is, translated from Latin, the "lifter of both the upper lip and of the wing of the nose". The muscle is attached to the upper frontal process of the m ...
*
Depressor labii inferioris muscle The depressor labii inferioris (or quadratus labii inferioris) is a facial muscle. It helps to lower the bottom lip. Structure The depressor labii inferioris muscle arises from the lateral surface of the mandible. This is below the mental for ...
*
Levator anguli oris The levator anguli oris (caninus) is a facial muscle of the mouth arising from the canine fossa, immediately below the infraorbital foramen. It elevates angle of mouth medially. Its fibers are inserted into the angle of the mouth, intermingli ...
*
Buccinator muscle The bucinator () is a thin quadrilateral muscle occupying the interval between the maxilla and the Human mandible, mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity.Illustrated Anatom ...
*
Mentalis The mentalis muscle is a paired central Skeletal muscle, muscle of the lower lip, situated at the tip of the chin. It originates from the mentum of the mandible, and inserts into the soft tissue of the chin. It is sometimes referred to as the "pou ...
The
platysma The platysma muscle or platysma is a :wikt:superficial, superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the ...
is supplied by the facial nerve. Although it is mostly in the neck and can be grouped with the neck muscles by location, it can be considered a muscle of facial expression due to its common nerve supply. The
stylohyoid muscle 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. ...
,
stapedius The stapedius is the smallest skeletal muscle in the human body. At just over one millimeter in length, its purpose is to stabilize the smallest bone in the body, the stapes or stirrup bone of the middle ear. Structure The stapedius emerges from ...
and posterior belly of the
digastric muscle The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') 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 ...
are also supplied by the facial nerve, but are not considered muscles of facial expression.


Facial muscles by type of movement


Development

The facial muscles are derived from the second branchial/
pharyngeal arch The pharyngeal arches, also known as visceral arches'','' are transient structures seen in the Animal embryonic development, embryonic development of humans and other vertebrates, that are recognisable precursors for many structures. In fish, t ...
. They, like the branchial arches, originally derive from neural crest cells. In humans, they typically begin forming around the eighth week of embryonic development.


Clinical significance

An inability to form facial expressions on one side of the face may be the first sign of damage to the nerve of these muscles. Damage to the facial nerve results in
facial paralysis Facial nerve paralysis is a common problem that involves the paralysis of any structures innervated by the facial nerve. The pathway of the facial nerve is long and relatively convoluted, so there are a number of causes that may result in facial ...
of the muscles of facial expression on the involved side. Paralysis is the loss of voluntary muscle action; the facial nerve has become damaged permanently or temporarily. This damage can occur with a
stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...
,
Bell palsy Bell's palsy is a type of facial paralysis that results in a temporary inability to control the facial muscles on the affected side of the face. In most cases, the weakness is temporary and significantly improves over weeks. Symptoms can vary fr ...
, or parotid salivary gland cancer (malignant neoplasm) because the facial nerve travels through the gland. The
parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the m ...
can also be damaged permanently by surgery or temporarily by trauma. These situations of paralysis not only inhibit facial expression but also seriously impair the patient’s ability to speak, either permanently or temporarily.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, page 89


See also

*
Masticatory muscles The four classical muscles of mastication elevate the mandible (closing the jaw) and move it forward/backward and laterally, facilitating biting and chewing. Other muscles are responsible for opening the jaw, namely the geniohyoid, mylohyoid, and ...
*
Facial Action Coding System The Facial Action Coding System (FACS) is a system to taxonomize human facial movements by their appearance on the face, based on a system originally developed by a Swedish anatomist named Carl-Herman Hjortsjö. It was later adopted by Paul E ...
* Modiolus


References


External links


ARTNATOMY: Anatomical Basis of Facial Expression Learning Tool
*
Facial muscles at PracticeAnatomyMuscles of Facial Expression
{{Authority control Muscles of the head and neck
Muscles 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 ...
Otorhinolaryngology