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 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 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 * Temporoparietalis muscle * Procerus muscle * Nasalis muscle * Depressor septi nasi muscle * Orbicularis oculi muscle * Corrugator supercilii muscle * 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 and posterior) * Orbicularis oris muscle * Depressor anguli oris muscle * Risorius * Zygomaticus major muscle * Zygomaticus minor muscle * Levator labii superioris * Levator labii superioris alaeque nasi muscle * Depressor labii inferioris muscle * Levator anguli oris * Buccinator muscle * Mentalis The platysma 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, stapedius and posterior belly of the digastric muscle 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. 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 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, or parotid salivary gland cancer (malignant neoplasm) because the facial nerve travels through the gland. The parotid gland 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

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