FACTOID # 8: Bookworms: Vermont has the highest number of high school teachers per capita and third highest number of librarians per capita.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Facial nerve
Nerve: Facial nerve
Cranial nerve VII
The nerves of the scalp, face, and side of neck.
Latin nervus facialis
Gray's subject #202 901
MeSH Facial+Nerve
Dorlands/Elsevier n_05/12565770

The facial nerve is the seventh (VII) of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and taste to the anterior two-thirds of the tongue. It also supplies preganglionic parasympathetic fibers to several head and neck ganglia. Image File history File links This is a lossless scalable vector image. ... Image File history File links Size of this preview: 512 × 600 pixelsFull resolution (620 × 726 pixel, file size: 120 KB, MIME type: image/png) Same as Gray805. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo. ... Cranial nerves Cranial nerves are nerves that emerge directly from the brain in contrast to spinal nerves which emerge from segments of the spinal cord. ... Position of the pons in the human brain The pons (sometimes pons Varolii after Costanzo Varolio) is a knob on the brain stem. ... The medulla oblongata is the lower portion of the brainstem. ... Taste is one of the traditional five senses and refers to the ability to detect the flavor of foodstuffs and other substances (e. ... This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... Anatomy and Physiology of the A.N.S. In contrast to the voluntary nervous system, the involuntary or autonomic nervous system is responsible for homeostasis, maintaining a relatively constant internal environment by controlling such involuntary functions as digestion, respiration, and metabolism, and by modulating blood pressure. ... GÅNGLÎÅ is a 1 man electronic grindcore band from Los Angeles California that began in August of 1999. ...

Contents

Structure

The motor part of the facial nerve arises from the facial nerve nucleus in the pons while the sensory part of the facial nerve arises from the nervus intermedius. The cranial nerve motor nucleus of the facial nerve is located in the lower pons. ... Position of the pons in the human brain The pons (sometimes pons Varolii after Costanzo Varolio) is a knob on the brain stem. ... The nervus intermedius, or intermediate nerve, is the part of the facial nerve (cranial nerve VII) located between the motor component of the facial nerve and the vestibulocochlear nerve (cranial nerve VIII). ...


The motor part of the facial nerve enters the petrous temporal bone into the internal auditory meatus (intimately close to the inner ear) then runs a tortuous course (including two tight turns) through the facial canal, emerges from the stylomastoid foramen and passes through the parotid gland, where it divides into five major branches. Though it passes through the parotid gland, it does not innervate the gland. This action is the responsibility of cranial nerve IX, the glossopharyngeal nerve. The temporal bones (os temporales) are situated at the sides and base of the skull. ... Near the center of the posterior surface of the temporal bone is a large orifice, the internal acoustic meatus (or internal auditory meatus), the size of which varies considerably; its margins are smooth and rounded, and it leads into a short canal, about 1 cm. ... The inner ear comprises both: the organ of hearing (the cochlea) and the labyrinth or vestibular apparatus, the organ of balance located in the inner ear that consists of three semicircular canals and the vestibule. ... The facial canal is a canal running from the internal acoustic meatus to the stylomastoid foramen. ... Between the styloid and mastoid processes is the stylomastoid foramen; it is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery. ... For the toad wart, see parotoid gland. ... The glossopharyngeal nerve is the ninth of twelve cranial nerves. ...


Inside one of the tight turns in the facial canal, the facial nerve forms the geniculate ganglion. Mark Hartley: 01946841665 i am gay and call me for bum sex. ...


No other nerve in the body travels such a long distance through a bony canal.


Branches

Inside the facial canal

  • Greater petrosal nerve - provides parasympathetic innervation to lacrimal gland, as well as special taste sensory fibers to the palate via the nerve of pterygoid canal.
  • Nerve to stapedius - provides motor innervation for stapedius muscle in middle ear
  • Chorda tympani - provides parasympathetic innervation to submandibular and sublingual glands and special sensory taste fibers for the anterior 2/3 of the tongue.

The greater petrosal nerve is a nerve in the skull that branches from the facial nerve; it forms part of a chain of nerves that innervates the lacrimal gland. ... The nerve of the pterygoid canal (Vidian nerve), formed by the junction of the great petrosal nerve and the deep petrosal nerve in the cartilaginous substance which fills the foramen lacerum, passes forward, through the pterygoid canal, with the corresponding artery, and is joined by a small ascending sphenoidal branch... The Nerve to the Stapedius (tympanic branch) arises opposite the pyramidal eminence. ... The stapedius is the smallest striated muscle in the human body. ... The chorda tympani are nerves of special sensation given off the facial nerve (VII) inside the skull. ...

Outside skull (distal to stylomastoid foramen)

A helpful mnemonic device for remembering the major branches are the phrases: "To Zanzibar By Motor Car", "Two Zebras Bit My Cat", "Tell Ziggy Bob Marley Called", "Two Zulus Buggered Michael Caine" or "Ten Zulus Buggered My Cat" Between the styloid and mastoid processes is the stylomastoid foramen; it is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery. ... The Posterior Auricular Nerve arises close to the stylo-mastoid foramen, and runs upward in front of the mastoid process; here it is joined by a filament from the auricular branch of the vagus, and communicates with the posterior branch of the great auricular, and with the lesser occipital. ... The Temporal branches of the facial nerve cross the zygomatic arch to the temporal region, supplying the Auriculares anterior and superior, and joining with the zygomaticotemporal branch of the maxillary, and with the auriculotemporal branch of the mandibular. ... The Zygomatic branches of the facial nerve (malar branches) run across the zygomatic bone to the lateral angle of the orbit, where they supply the Orbicularis oculi, and join with filaments from the lacrimal nerve and the zygomaticofacial branch of the maxillary nerve. ... The Buccal Branches of the facial nerve (infraorbital branches), of larger size than the rest of the branches, pass horizontally forward to be distributed below the orbit and around the mouth. ... The Marginal mandibular branch of facial nerve passes forward beneath the Platysma and Triangularis, supplying the muscles of the lower lip and chin, and communicating with the mental branch of the inferior alveolar nerve. ... The cervical branch of the facial nerve runs forward beneath the Platysma, and forms a series of arches across the side of the neck over the suprahyoid region. ... Map of Zanzibars main island Zanzibar is part of Tanzania Coordinates: , Country Tanzania Islands Unguja and Pemba Capital Zanzibar City Settled AD 1000 Government  - Type semi-autonomous part of Tanzania  - President Amani Abeid Karume Area  - Both Islands  637 sq mi (1,651 km²) Population (2004)  - Both Islands 1,070... Robert Bob Nesta Marley OM (February 6, 1945 – May 11, 1981) was a Jamaican singer, songwriter, guitarist, and political activist. ... Sir Maurice Joseph Micklewhite, Jr. ...


Function

Efferent

Its main function is motor control of most of the muscles of facial expression. It also innervates the posterior belly of the digastric muscle, the stylohyoid muscle, and the stapedius muscle of the middle ear. All of these muscles are striated muscles of branchiomeric origin developing from the 2nd pharyngeal arch. ... The Digastric is a muscle of the human body. ... The Stylohyoid muscle is a slender muscle, lying in front of, and above the posterior belly of the digastric muscle. ... The stapedius is the smallest striated muscle in the human body. ... The ear is the sense organ that detects sounds. ...


The facial also supplies parasympathetic fibers to the submandibular gland and sublingual glands via chorda tympani and the submandibular ganglion. Parasympathetic innervation serves to increase the flow of saliva from these glands. It also supplies parasympathetic innervation to the nasal mucosa and the lacrimal gland via the pterygopalatine ganglion. Autonomic nervous system innervation, showing the sympathetic and parasympathetic (craniosacral) systems, in red and blue, respectively The parasympathetic nervous system is one of three divisions of the autonomic nervous system. ... The submandibular gland is one of the salivary glands, responsible for producing saliva. ... The sublingual glands are salivary glands in the mouth. ... The chorda tympani are nerves of special sensation given off the facial nerve (VII) inside the skull. ... The submandibular ganglion (or submaxillary ganglion in older texts) is of small size and is fusiform in shape. ... The lacrimal glands are paired glands, one for each eye, that secrete the aqueous layer of the tear film. ... The sphenopalatine ganglion is a parasympathetic ganglion found in the spheno-maxillary fossa. ...


Afferent

In addition, it receives taste sensations from the anterior two-thirds of the tongue and sends them to the nucleus of solitary tract. The facial nerve also supplies a small amount of afferent innervation to the oropharynx above the palatine tonsil. There is also a small amount of cutaneous sensation carried by the nervus intermedius from the skin in and around the auricle (earlobe). Taste is one of the traditional five senses and refers to the ability to detect the flavor of foodstuffs and other substances (e. ... This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... The pharynx is the part of the digestive system of many animals immediately behind the mouth and in front of the esophagus. ... Most commonly, the term tonsils refers to the palatine tonsils that can be seen in the back of the throat. ... The nervus intermedius, or intermediate nerve, is the part of the facial nerve (cranial nerve VII) located between the motor component of the facial nerve and the vestibulocochlear nerve (cranial nerve VIII). ... Auricle has the following meanings: The external portion of the ear. ...


Location of Cell Bodies

The cell bodies for the facial nerve are grouped in anatomical areas called nuclei or ganglia. The cell bodies for the afferent nerves are found in the the geniculate ganglion for both taste and general afferent sensation. The cell bodies for muscular efferent nerves are found in the facial motor nucleus whereas the cell bodies for the parasympathetic efferent nerves are found in the superior salivatory nucleus. In neuroanatomy, a nucleus is a central nervous system structure that is composed mainly of gray matter, and which acts as a hub or transit point for electrical signals in a single neural subsystem. ... This is a dorsal root ganglion (DRG) from a chicken embryo (around stage of day 7) after incubation overnight in NGF growth medium stained with anti-neurofilament antibody. ... Mark Hartley: 01946841665 i am gay and call me for bum sex. ... The facial motor nucleus is a collection of neurons in the brainstem that belong to the facial nerve (cranial nerve VII). ... The Superior salivary nucleus (or superior salivatory nucleus) of the facial nerve is a visceromotor cranial nerve nucleus located in the pontine tegmentum. ...


Pathology

People may suffer from acute facial nerve paralysis, which is usually manifested by facial paralysis. Bell's palsy is one type of idiopathic acute facial nerve paralysis, which is more accurately described as a multiple cranial nerve ganglionitis that involves the facial nerve, and most likely results from viral infection and also sometimes as a result of Lyme disease. Acute facial nerve paralysis is a common problem that involves the paralysis of any structures innervated by the facial nerve. ... Bells palsy (or facial palsy) is characterised by facial drooping on the affected half, due to malfunction of the facial nerve (VII cranial nerve), which controls the muscles of the face. ... Idiopathic means arising spontaneously or from an obscure or unknown cause. ...


Testing the facial nerve

Voluntary facial movements, such as wrinkling the brow, showing teeth, frowning, closing the eyes tightly (lagophthalmos)[1] , pursing the lips and puffing out the cheeks, all test the facial nerve. There should be no noticeable asymmetry. Lagophthalmos describes difficulty in complete closure of the eyelid over the eyeball. ...


In an upper motor neuron lesion, called central seven, only the lower part of the face on the opposite side will be affected, due to the bilateral control to the upper facial muscles. Upper motor neurons are any neurons that carry motor information down to the final common pathway, that is, any neurons that are not directly responsible for stimulating the target muscle. ... Central seven, also called central facial palsy, is a disease characterized by paralysis of the lower half of one side of the face. ...


Lower motor neuron lesions can result in Bell's palsy, manifested as both upper and lower facial weakness on the same side of the lesion. Lower motor neurons (LMNs) are the motoneurons connecting the brainstem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles. ... Bells palsy (or facial palsy) is characterised by facial drooping on the affected half, due to malfunction of the facial nerve (VII cranial nerve), which controls the muscles of the face. ...


Taste can be tested on the anterior of the tongue, this can be tested with a swab dipped in a flavoured solution, or with electronic stimulation (similar to putting your tongue on a battery).


Additional images

External links


 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m