Posterior auricular muscle

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Posterior auricular muscle
Gray906.png
The muscles of the auricula
Auricularis posterior.png
Auricula in context.
Details
Origin Mastoid process of temporal bone
Insertion Posterior part of auricle of outer ear
Artery Posterior auricular artery
Vein Posterior auricular vein
Nerve Posterior auricular nerve of facial nerve (VII)
Actions Pulls ear backward
Identifiers
Latin musculus auricularis posterior
TA98 A04.1.03.022
TA2 2091
FMA 46857
Anatomical terms of muscle

The posterior auricular muscle is a muscle behind the auricle of the outer ear. It arises from the mastoid part of the temporal bone, and inserts into the lower part of the cranial surface of the auricle of the outer ear. It draws the auricle backwards, usually a very slight effect.

Contents

Structure

The posterior auricular muscle is found behind the auricle of the outer ear. [1] It consists of two or three fleshy fasciculi. These arise from the mastoid part of the temporal bone by short aponeurotic fibers. [1] They insert into the lower part of the cranial surface of the auricle of the outer ear. [1]

The posterior auricular muscle is supplied by branches of the posterior auricular artery, which continues deep to the muscle. [2] It is drained by the posterior auricular vein that accompanies the artery. [2]

Nerve supply

The posterior auricular muscle is supplied by the posterior auricular nerve, a branch of the facial nerve (VII). [2] [3]

Function

The posterior auricular nerve draws the auricle of the outer ear backwards. [2] This effect is usually very slight, although some people can wiggle their ears due to a more significant muscle movement. [2]

Postauricular reflex

The postauricular reflex is a vestigial myogenic [4] muscle response in humans that acts to pull the ear upward and backward. [5] Research suggests neural circuits for auricle orienting have survived in a vestigial state for over 25 million years. It is often assumed the reflex is a vestigial Preyer reflex (also known as the pinna reflex). [6] [7]

A study on auriculomotor activity found that in the presence of sudden, surprising sounds, the muscles around the ear closest to the direction of the sound would respond by moving involuntarily, causing the pinna to be pulled backwards and flatten. [8]

Clinical significance

If the posterior auricular muscle inserts into an unusual part of the auricle of the outer ear, this can cause protruding ears. [1] In one study, the muscle was found to be absent in 5% of people. [9]

See also

Related Research Articles

<span class="mw-page-title-main">Outer ear</span> Outer part of the ear

The outer ear, external ear, or auris externa is the external part of the ear, which consists of the auricle and the ear canal. It gathers sound energy and focuses it on the eardrum.

<span class="mw-page-title-main">Facial nerve</span> Cranial nerve VII, for the face and tasting

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 taste sensations from the anterior two-thirds of the tongue. The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI and anterior to cranial nerve VIII.

<span class="mw-page-title-main">Lesser occipital nerve</span> Nerve of the head and neck

The lesser occipital nerve is a cutaneous spinal nerve of the cervical plexus. It arises from second cervical (spinal) nerve (C2). It innervates the skin of the back of the upper neck and of the scalp posterior to the ear.

<span class="mw-page-title-main">Great auricular nerve</span> Cutaneous nerve of the head

The great auricular nerve is a cutaneous (sensory) nerve of the head. It originates from the second and third cervical (spinal) nerves (C2-C3) of the cervical plexus. It provides sensory innervation to the skin over the parotid gland and the mastoid process, parts of the outer ear, and to the parotid gland and its fascia.

<span class="mw-page-title-main">Ear</span> Organ of hearing and balance

An ear is the organ that enables hearing and body balance using the vestibular system. In mammals, the ear is usually described as having three parts: the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. Since the outer ear is the only visible portion of the ear in most animals, the word "ear" often refers to the external part alone. The middle ear includes the tympanic cavity and the three ossicles. The inner ear sits in the bony labyrinth, and contains structures which are key to several senses: the semicircular canals, which enable balance and eye tracking when moving; the utricle and saccule, which enable balance when stationary; and the cochlea, which enables hearing. The ear canal is cleaned via earwax, which naturally migrates to the auricle. The ears of vertebrates are placed somewhat symmetrically on either side of the head, an arrangement that aids sound localization.

<span class="mw-page-title-main">Auricle (anatomy)</span> Visible part of the ear that is outside the head

The auricle or auricula is the visible part of the ear that is outside the head. It is also called the pinna, a term that is used more in zoology.

<span class="mw-page-title-main">Cervical plexus</span> Network of nerves in the neck

The cervical plexus is a nerve plexus of the anterior rami of the first four cervical spinal nerves C1-C4. The cervical plexus provides motor innervation to some muscles of the neck, and the diaphragm; it provides sensory innervation to parts of the head, neck, and chest.

<span class="mw-page-title-main">Digastric muscle</span> Small muscle located under the jaw in mammals

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.

Otoplasty is a procedure for correcting the deformities and defects of the auricle, whether these defects are congenital conditions or caused by trauma. Otoplastic surgeons may reshape, move, or augment the cartilaginous support framework of the auricle to correct these defects.

<span class="mw-page-title-main">Auricular branch of vagus nerve</span> Nerve of the head and neck

The auricular branch of the vagus nerve is often termed the Alderman's nerve or Arnold's nerve. The auricular branch of the vagus nerve supplies sensory innervation to the skin of the ear canal, tragus, and auricle.

<span class="mw-page-title-main">Occipital artery</span>

The occipital artery is a branch of the external carotid artery that provides arterial supply to the back of the scalp, sternocleidomastoid muscles, and deep muscles of the back and neck.

<span class="mw-page-title-main">Posterior auricular artery</span> Small artery

The posterior auricular artery is a small artery that arises from the external carotid artery. It ascends along the side of the head. It supplies several muscles of the neck and several structures of the head.

<span class="mw-page-title-main">Mastoid part of the temporal bone</span> Back part of the sides of the skull base

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.

<span class="mw-page-title-main">Superior ganglion of vagus nerve</span> Sensory ganglion within Jugular foramen

The superior ganglion of the vagus nerve is a sensory ganglion of the peripheral nervous system. It is located within the jugular foramen, where the vagus nerve exits the skull. It is smaller than and proximal to the inferior ganglion of the vagus nerve.

<span class="mw-page-title-main">Posterior auricular nerve</span> Nerve of the head

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.

<span class="mw-page-title-main">Transverse muscle of auricle</span> Muscle of the outer ear

The transverse muscle of auricle is an intrinsic muscle of the outer ear.

A vestigial response or vestigial reflex in a species is a response that has lost its original function. In humans, vestigial responses include ear perking, goose bumps and the hypnic jerk.

<span class="mw-page-title-main">Superior auricular muscle</span> Muscle that draws the auricle of the outer ear upwards

The superior auricular muscle is a muscle above the auricle of the outer ear. It originates from the epicranial aponeurosis, and inserts into the upper part of the medial surface of the auricle. It draws the auricle upwards.

<span class="mw-page-title-main">Anterior auricular muscle</span> Muscle connectingthe epicranial aponeurosis to the helix of the ear

The anterior auricular muscle, the smallest of the three auricular muscles, is thin and fan-shaped, and its fibers are pale and indistinct. It arises from the lateral edge of the epicranial aponeurosis, and its fibers converge to be inserted into a projection on the front of the helix.

The oculo-auricular phenomenon, first described by Kinnier Wilson in 1908, is the phenomenon of an extreme lateral gaze inducing a slight but perceptible backwards movement of the upper part of the pinna. It is a muscle synergy involving the Abducens innervated lateral rectus muscle, an external muscle of the eye, and the facial innervated posterior auricular muscle, an external muscle of the ear. Wilson's phenomenon had attracted attention at the time because of his renown and for its implications regarding Darwin's theory of natural selection. According to, "In patients with brainstem disease abnormal transverse auricular muscle coactivation is characterized by absence of activity in one or both ear muscles during lateral gaze in either or both directions."

References

  1. 1 2 3 4 Yotsuyanagi, Takatoshi; Yamauchi, Makoto; Yamashita, Ken; Sugai, Asuka; Gonda, Ayako; Kitada, Ayaka; Saito, Tamotsu; Urushidate, Satoshi (July 2015). "Abnormality of Auricular Muscles in Congenital Auricular Deformities". Plastic and Reconstructive Surgery . 136 (1): 78e–88e. doi:10.1097/PRS.0000000000001383. ISSN   0032-1052. PMID   26111335. S2CID   23651843.
  2. 1 2 3 4 5 Niamtu, Joseph (2018). "8 - Cosmetic Otoplasty and Related Ear Surgery". Cosmetic Facial Surgery (2nd ed.). Edinburgh: Elsevier. pp. 473–532. doi:10.1016/B978-0-323-39393-5.00008-X. ISBN   978-0-323-39402-4. OCLC   976037123.
  3. Barral, Jean-Pierre; Croibier, Alain (2009). "25 - Ear". Manual Therapy for the Cranial Nerves. Edinburgh: Churchill Livingstone / Elsevier. pp. 227–238. doi:10.1016/B978-0-7020-3100-7.50028-8. ISBN   978-0-7020-3736-8. OCLC   460904284.
  4. Benning, Stephen D. (2018-04-05). "The Postauricular Reflex as a Measure of Attention and Positive Emotion". Oxford Handbooks Online. doi:10.1093/oxfordhb/9780199935291.013.74. ISBN   978-0-19-993529-1.
  5. Benning, Stephen D. (2011-03-01). "Postauricular and superior auricular reflex modulation during emotional pictures and sounds". Psychophysiology. 48 (3): 410–414. doi:10.1111/j.1469-8986.2010.01071.x. ISSN   1469-8986. PMC   2962877 . PMID   20636290.
  6. Hackley, Steven A. (2015-10-01). "Evidence for a vestigial pinna-orienting system in humans". Psychophysiology. 52 (10): 1263–1270. doi:10.1111/psyp.12501. ISSN   1469-8986. PMID   26211937.
  7. "ZFIN Behavior Ontology: pinna reflex". zfin.org. Retrieved 2020-01-05.
  8. Strauss, Daniel J; Corona-Strauss, Farah I; Schroeer, Andreas; Flotho, Philipp; Hannemann, Ronny; Hackley, Steven A (2020-07-03). "Vestigial auriculomotor activity indicates the direction of auditory attention in humans". eLife. 9: e54536. doi: 10.7554/eLife.54536 . ISSN   2050-084X. PMC   7334025 . PMID   32618268.
  9. Benning, Stephen D. (2018-04-05). "The Postauricular Reflex as a Measure of Attention and Positive Emotion". Oxford Handbook Topics in Psychology. Vol. 1. Oxford University Press. doi:10.1093/oxfordhb/9780199935291.013.74. ISBN   978-0-19-993529-1.