The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a

cranial nerve Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and ...

that exits the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is cont ...

from the sides of the upper

medulla Medulla or Medullary may refer to: Science * Medulla oblongata, a part of the brain stem * Renal medulla, a part of the kidney * Adrenal medulla, a part of the adrenal gland * Medulla of ovary, a stroma in the center of the ovary * Medulla of t ...

, just anterior (closer to the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes th ...

) to the

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right ...

. Being a mixed nerve (sensorimotor), it carries afferent sensory and efferent motor information. The motor division of the glossopharyngeal nerve is derived from the basal plate of the

embryo An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

nic

medulla oblongata The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...

, whereas the sensory division originates from the

cranial neural crest The cranial neural crest is one of the four regions of the neural crest. The cranial neural crest arises in the anterior and populates the face and the pharyngeal arches giving rise to bones, cartilage, nerves and connective tissue. The endocraniu ...

Structure

From the anterior portion of the

, the glossopharyngeal nerve passes laterally across or below the flocculus, and leaves the skull through the central part of the

jugular foramen A jugular foramen is one of the two (left and right) large foramina (openings) in the base of the skull, located behind the carotid canal. It is formed by the temporal bone and the occipital bone. It allows many structures to pass, including the i ...

. From the superior and inferior ganglia in jugular foramen, it has its own sheath of

dura mater In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...

. The inferior ganglion on the inferior surface of petrous part of temporal is related with a triangular depression into which the aqueduct of cochlea opens. On the inferior side, the glossopharyngeal nerve is lateral and anterior to the

and

accessory nerve The accessory nerve, also known as the eleventh cranial nerve, cranial nerve XI, or simply CN XI, is a cranial nerve that supplies the sternocleidomastoid and trapezius muscles. It is classified as the eleventh of twelve pairs of cranial nerv ...

. In its passage through the foramen (with X and XI), the glossopharyngeal nerve passes between the

internal jugular vein The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posteri ...

and

internal carotid artery The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these b ...

. It descends in front of the latter vessel and beneath the styloid process and the muscles connected with it, to the posterior lower border of the

stylopharyngeus muscle The stylopharyngeus is a muscle in the head that stretches between the temporal styloid process and the pharynx. Structure The stylopharyngeus is a long, slender muscle, cylindrical above, flattened below. It arises from the medial side of the ...

. It then curves forward, forming an arch on the side of the neck and lying upon the

stylopharyngeus The stylopharyngeus is a muscle in the head that stretches between the temporal styloid process and the pharynx. Structure The stylopharyngeus is a long, slender muscle, cylindrical above, flattened below. It arises from the medial side of the ...

and

middle pharyngeal constrictor The middle pharyngeal constrictor is a fan-shaped muscle located in the neck. It is one of three pharyngeal constrictors. Similarly to the superior and inferior pharyngeal constrictor muscles, the middle pharyngeal constrictor is innervated by a ...

muscle. From there, it passes under cover of the

hyoglossus The hyoglossus, thin and quadrilateral, arises from the side of the body and from the whole length of the greater cornu of the hyoid bone, and passes almost vertically upward to enter the side of the tongue, between the styloglossus and the infe ...

muscle and is finally distributed to the

palatine tonsil Palatine tonsils, commonly called the tonsils and occasionally called the faucial tonsils, are tonsils located on the left and right sides at the back of the throat, which can often be seen as flesh-colored, pinkish lumps. Tonsils only present as ...

, the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

of the fauces and base of the

tongue The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...

, and the serous glands of the

mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...

Branches

tympanic nerve The tympanic nerve (Jacobson’s nerve) is a branch of the glossopharyngeal nerve found near the ear. It gives sensation to the middle ear, the Eustachian tube, the parotid gland, and mastoid air cells. It gives parasympathetic to supply to the ...

* stylopharyngeal nerve * tonsillar nerve *

carotid sinus nerve The carotid branch of the glossopharyngeal nerve (carotid sinus nerve or Hering's nerve) is a small branch of the glossopharyngeal nerve that innervates the carotid sinus and carotid body. It is a branch of the glossopharyngeal nerve that runs down ...

* Branches to the posterior third of tongue * lingual branches * A communicating branch to the

Note: The glossopharyngeal nerve contributes in the formation of the pharyngeal plexus along with the vagus nerve. The glossopharyngeal nerve has five distinct general functions: #Branchial motor (

special visceral efferent Special visceral efferent fibers (SVE) are the efferent nerve fibers that provide motor innervation to the muscles of the pharyngeal arches in humans, and the branchial arches in fish. Some sources prefer the term "branchiomotor" or "branchial eff ...

)supplies the

. #Visceral motor (

general visceral efferent General visceral efferent fibers (GVE) or visceral efferents or autonomic efferents, are the efferent nerve fibers of the autonomic nervous system (also known as the ''visceral efferent nervous system'' that provide motor innervation to smooth m ...

)provides

parasympathetic The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of t ...

innervation of 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 man ...

via the otic ganglion #Visceral sensory (

general visceral afferent The general visceral afferent (GVA) fibers conduct sensory impulses (usually pain or reflex sensations) from the internal organs, glands, and blood vessels to the central nervous system. They are considered to be part of the visceral nervous sy ...

)carries visceral sensory information from the

carotid sinus In human anatomy, the carotid sinus is a dilated area at the base of the internal carotid artery just superior to the bifurcation of the internal carotid and external carotid at the level of the superior border of thyroid cartilage. The carotid ...

and

carotid body The carotid body is a small cluster of chemoreceptor cells, and supporting sustentacular cells. The carotid body is located in the adventitia, in the bifurcation (fork) of the common carotid artery, which runs along both sides of the neck. The ca ...

. #General sensory (

general somatic afferent The general somatic afferent fibers (GSA, or somatic sensory fibers) afferent fibers arise from neurons in sensory ganglia and are found in all the spinal nerves, except occasionally the first cervical, and conduct impulses of pain, touch and temp ...

)provides general sensory information from inner surface of the

tympanic membrane In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the air ...

, upper

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struc ...

(GVA), and the posterior one-third of the

. #Visceral afferent (

special visceral afferent A Special visceral afferent fibers (SVA) is a afferent fiber that develop in association with the gastrointestinal tract. They carry the special senses of smell (olfaction) and taste (gustation). The cranial nerves containing SVA fibers are the olfa ...

)provides

taste The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). Taste is the perception produced or stimulated when a substance in the mouth reacts chemically with taste receptor ...

sensation from the posterior one-third of the

, including

circumvallate papillae Lingual papillae (singular papilla) are small structures on the upper surface of the tongue that give it its characteristic rough texture. The four types of papillae on the human tongue have different structures and are accordingly classified as c ...

. The glossopharyngeal nerve as noted above is a mixed nerve consisting of both sensory and motor nerve fibers. The sensory fibers' origin include the pharynx, middle ear, posterior one-third of the tongue (including taste buds); and the carotid body and sinus. These fibers terminate at the

. The motor fibers' origin is the medulla oblongata, and they terminate at the parotid salivary gland, the glands of the posterior tongue, and the

muscle (which dilates the pharynx during swallowing).

Overview of branchial motor component

The branchial motor component of CN IX provides voluntary control of the stylopharyngeus muscle, which elevates the pharynx during swallowing and speech. Origin and central course The branchial motor component originates from the nucleus ambiguus in the reticular formation of the medulla Rostral medulla. Fibers leaving the

nucleus ambiguus The nucleus ambiguus ("ambiguous nucleus" in English) is a group of large motor neurons, situated deep in the medullary reticular formation named by Jacob Clarke. The nucleus ambiguus contains the cell bodies of neurons that innervate the muscles ...

travel anteriorly and laterally to exit the medulla, along with the other components of CN IX, between the olive and the

inferior cerebellar peduncle The upper part of the posterior district of the medulla oblongata is occupied by the inferior cerebellar peduncle, a thick rope-like strand situated between the lower part of the fourth ventricle and the roots of the glossopharyngeal and vagus ner ...

. Intracranial course Upon emerging from the lateral aspect of the medulla the branchial motor component joins the other components of CN IX to exit the skull via the jugular foramen. The glossopharyngeal fibers travel just anterior to the cranial nerves X and XI, which also exit the skull via the

. Extra-cranial course and final innervation Upon exiting the skull the branchial motor fibers descend deep to the

temporal styloid process The temporal styloid process is a slender bony process of the temporal bone extending downward and forward from the undersurface of the temporal bone just below the ear. The styloid process gives attachments to several muscles, and ligaments. Stru ...

and wrap around the posterior border of the

before innervating it. Voluntary control of the stylopharyngeus muscle Signals for the voluntary movement of

originate in the pre-motor and motor cortex (in association with other cortical areas) and pass via the

corticobulbar In neuroanatomy, the corticobulbar (or corticonuclear) tract is a two-neuron white matter motor pathway connecting the motor cortex in the cerebral cortex to the medullary pyramids, which are part of the brainstem's medulla oblongata (also called ...

tract in the genu of the internal capsule to synapse bilaterally on the ambiguus nuclei in the medulla.

Overview of visceral motor component

Parasympathetic component of the glossopharyngeal nerve that innervates the ipsilateral parotid gland. Origin and central course The

preganglionic In the autonomic nervous system, fibers from the CNS to the ganglion are known as preganglionic fibers. All preganglionic fibers, whether they are in the sympathetic division or in the parasympathetic division, are cholinergic (that is, these f ...

nerve fibers originate in the

inferior salivatory nucleus The salivatory nuclei are the superior salivatory nucleus, and the inferior salivatory nucleus that innervate the salivary glands. They are located in the pontine tegmentum in the brainstem. They both are examples of cranial nerve nuclei. The su ...

of the rostral medulla and travel anteriorly and laterally to exit the brainstem between the medullary olive and the

with the other components of CN IX. Note: These neurons do not form a distinct nucleus visible on cross-section of the brainstem. The position indicated on the diagram is representative of the location of the cell bodies of these fibers. Intracranial course Upon emerging from the lateral aspect of the medulla, the visceral motor fibers join the other components of CN IX to enter the

. Within the jugular foramen, there are two glossopharyngeal ganglia that contain nerve cell bodies that mediate general, visceral, and special sensation. The visceral motor fibers pass through both ganglia without synapsing and exit the inferior ganglion with CN IX general sensory fibers as the

. Before exiting the jugular foramen, the tympanic nerve enters the

petrous portion of the temporal bone The petrous part of the temporal bone is pyramid-shaped and is wedged in at the base of the skull between the sphenoid and occipital bones. Directed medially, forward, and a little upward, it presents a base, an apex, three surfaces, and three an ...

and ascends via the

inferior tympanic canaliculus The inferior tympanic canaliculus is a small passage of the tympanic branch of the glossopharyngeal nerve and inferior tympanic artery. In the bony ridge dividing the carotid canal from the jugular fossa is the small inferior tympanic canaliculu ...

to the

tympanic cavity The tympanic cavity is a small cavity surrounding the bones of the middle ear. Within it sit the ossicles, three small bones that transmit vibrations used in the detection of sound. Structure On its lateral surface, it abuts the external auditory ...

. Within the tympanic cavity the tympanic nerve forms a

plexus In neuroanatomy, a plexus (from the Latin term for "braid") is a branching network of vessels or nerves. The vessels may be blood vessels (veins, capillaries) or lymphatic vessels. The nerves are typically axons outside the central nervous syste ...

on the surface of the promontory of the middle ear to provide general sensation. The visceral motor fibers pass through this plexus and merge to become the

lesser petrosal nerve The lesser petrosal nerve (also known as the small superficial petrosal nerve) is the general visceral efferent (GVE) component of the glossopharyngeal nerve (CN IX), carrying parasympathetic preganglionic fibers from the tympanic plexus to the pa ...

. The lesser petrosal nerve re-enters and travels through the temporal bone to emerge in the

middle cranial fossa The middle cranial fossa, deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior fossa by the clivus and the petrous crest. It is bounded in front by the pos ...

just lateral to the

greater petrosal nerve The greater petrosal nerve (or greater superficial petrosal nerve) is a nerve in the skull that branches from the facial nerve; it forms part of a chain of nerves that innervate the lacrimal gland. The preganglionic parasympathetic axons of this ne ...

. It then proceeds anteriorly to exit the skull via the foramen ovale along with the

mandibular nerve In neuroanatomy, the mandibular nerve (V) is the largest of the three divisions of the trigeminal nerve, the fifth cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which contain only aff ...

component of CN V (V3). Extra-cranial course and final innervations Upon exiting the skull, the lesser petrosal nerve synapses in the

otic ganglion The otic ganglion is a small parasympathetic ganglion located immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is functionally associated with the glossopharyngeal nerve and in ...

, which is suspended from the

immediately below the foramen ovale. Postganglionic fibers from the otic ganglion travel with the

auriculotemporal branch The auriculotemporal nerve is a branch of the mandibular nerve (CN V3) that runs with the superficial temporal artery and vein, and provides sensory innervation to various regions on the side of the head. Structure Origin The auriculotempor ...

of CN V3 to enter the substance of the

. Hypothalamic Influence Fibers from the

hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...

and

olfactory system The olfactory system, or sense of smell, is the sensory system used for smelling (olfaction). Olfaction is one of the special senses, that have directly associated specific organs. Most mammals and reptiles have a main olfactory system and an ac ...

project via the

dorsal longitudinal fasciculus Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

to influence the output of the

. Examples include: 1) dry mouth in response to fear (mediated by the hypothalamus); 2) salivation in response to smelling food (mediated by the olfactory system)

Overview of visceral sensory component

This component of CN IX innervates the baroreceptors of the

and chemoreceptors of the

. ;Peripheral and intracranial course. :Sensory fibers arise from the

and

at the common carotid artery bifurcation, ascend in the

, and join the other components of

CN IX The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper medulla, just anterior (closer to the nose) to the vagus nerve. Be ...

at the inferior glossopharyngeal ganglion. The cell bodies of these neurons reside in the inferior glossopharyngeal ganglion. The central processes of these neurons enter the skull via the

. ;Central course – visceral sensory component :Once inside the skull, the visceral sensory fibers enter the lateral medulla between the olive and the

and descend in the

solitary tract The solitary tract (tractus solitarius, or fasciculus solitarius), is a compact fiber bundle that extends longitudinally through the posterolateral region of the medulla oblongata. The solitary tract is surrounded by the solitary nucleus, and des ...

to synapse in the caudal

solitary nucleus In the human brainstem, the solitary nucleus, also called nucleus of the solitary tract, nucleus solitarius, and nucleus tractus solitarii, (SN or NTS) is a series of purely sensory nuclei (clusters of nerve cell bodies) forming a vertical column ...

. From the solitary nucleus, connections are made with several areas in the reticular formation and

to mediate cardiovascular and respiratory reflex responses to changes in blood pressure, and serum concentrations of CO2 and O2. Clinical correlation The visceral sensory fibers of CN IX mediate the afferent limb of the pharyngeal reflex in which touching the back of the pharynx stimulates the patient to gag (i.e., the gag reflex). The efferent signal to the musculature of the pharynx is carried by the branchial motor fibers of the vagus nerve.

Overview of somatic sensory component

This component of CN IX carries general sensory information (pain, temperature, and touch) from the skin of the external ear, internal surface of the tympanic membrane, the walls of the upper pharynx, and the posterior one-third of the tongue, anterior surface of the epiglottis, vallecula. ;Peripheral course :Sensory fibers from the skin of the external ear initially travel with the auricular branch of CN X, while those from the middle ear travel in the tympanic nerve as discussed above (CN IX visceral motor section). General sensory information from the upper pharynx and posterior one-third of the tongue travel via the pharyngeal branches of CN IX. These peripheral processes have their cell body in either the superior or inferior glossopharyngeal ganglion. ;Central course :The central processes of the general sensory neurons exit the glossopharyngeal ganglia and pass through the jugular foramen to enter the brainstem at the level of the medulla. Upon entering the medulla these fibers descend in the spinal trigeminal tract and synapse in the caudal spinal nucleus of the trigeminal.

Overview of special sensory component

The special sensory component of CN IX provides taste sensation from the posterior one-third of the tongue. ;Peripheral course :Special sensory fibers from the posterior one-third of the tongue travel via the pharyngeal branches of CN IX to the inferior glossopharyngeal ganglion where their cell bodies reside. ;Central course – special sensory component :The central processes of these neurons exit the inferior ganglion and pass through the jugular foramen to enter the brainstem at the level of the rostral medulla between the olive and inferior cerebellar peduncle. Upon entering the medulla, these fibers ascend in the tractus solitarius and synapse in the gustatory part of nucleus solitarius. Taste fibers from CN VII and X also ascend and synapse here. Ascending secondary neurons originating in nucleus solitarius project bilaterally to the ventral posteromedial (VPM) nuclei of the thalamus via the central tegmental tract. Tertiary neurons from the thalamus project via the posterior limb of the internal capsule to the inferior one-third of the primary sensory cortex (the gustatory cortex of the parietal lobe).

Associated brainstem nuclei

Solitary nucleus In the human brainstem, the solitary nucleus, also called nucleus of the solitary tract, nucleus solitarius, and nucleus tractus solitarii, (SN or NTS) is a series of purely sensory nuclei (clusters of nerve cell bodies) forming a vertical column ...

: taste from the posterior 1/3 of the tongue and information from carotid sinus baroreceptors and carotid body chemoreceptors * Spinal nucleus of the trigeminal nerve: Somatic sensory fibers from the internal surface of the tympanic membrane, middle ear, upper part of the pharynx, soft palate and posterior 1/3 of the tongue *

Nucleus ambiguus The nucleus ambiguus ("ambiguous nucleus" in English) is a group of large motor neurons, situated deep in the medullary reticular formation named by Jacob Clarke. The nucleus ambiguus contains the cell bodies of neurons that innervate the muscles ...

lower motor neuron Lower motor neurons (LMNs) are motor neurons located in either the anterior grey column, anterior nerve roots (spinal lower motor neurons) or the cranial nerve nuclei of the brainstem and cranial nerves with motor function (cranial nerve lower mo ...

s for the

muscle *

Inferior salivatory nucleus The salivatory nuclei are the superior salivatory nucleus, and the inferior salivatory nucleus that innervate the salivary glands. They are located in the pontine tegmentum in the brainstem. They both are examples of cranial nerve nuclei. The su ...

: preganglionic

neurons to the otic ganglion and then to the parotid gland

Functions

* It receives general somatic sensory fibers ( ventral trigeminothalamic tract) from the

tonsils The tonsils are a set of lymphoid organs facing into the aerodigestive tract, which is known as Waldeyer's tonsillar ring and consists of the adenoid tonsil, two tubal tonsils, two palatine tonsils, and the lingual tonsils. These organs play an ...

, the

middle ear The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear). The mammalian middle ear contains three ossicles, which transfer the vibrations of the eardrum into waves in the ...

and the posterior 1/3 of the tongue. * It receives special visceral sensory fibers (

) from the posterior 1/3 of the

. * It receives visceral sensory fibers from the

carotid bodies The carotid body is a small cluster of chemoreceptor cells, and supporting sustentacular cells. The carotid body is located in the adventitia, in the bifurcation (fork) of the common carotid artery, which runs along both sides of the neck. The ca ...

. * It supplies

fibers to the

via the

. * It supplies

motor fibers A motor neuron (or motoneuron or efferent neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly ...

, the only motor component of this cranial nerve. * It contributes to the pharyngeal plexus.

Clinical significance

Damage

Damage to the glossopharyngeal nerve can result in loss of taste sensation to the posterior one third of the tongue, and impaired

swallowing Swallowing, sometimes called deglutition in scientific contexts, is the process in the human or animal body that allows for a substance to pass from the mouth, to the pharynx, and into the esophagus, while shutting the epiglottis. Swallowing i ...

Examination

The clinical tests used to determine if the glossopharyngeal nerve has been damaged include testing the

gag reflex The pharyngeal reflex or gag reflex is a reflex muscular contraction of the back of the throat, evoked by touching the roof of the mouth, the back of the tongue, the area around the tonsils, the uvula, and the back of the throat. It, along with othe ...

of the mouth, asking the patient to

swallow The swallows, martins, and saw-wings, or Hirundinidae, are a family of passerine songbirds found around the world on all continents, including occasionally in Antarctica. Highly adapted to aerial feeding, they have a distinctive appearance. The ...

cough A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three pha ...

, and evaluating for speech impediments. The clinician may also test the posterior one-third of the tongue with bitter and sour substances to evaluate for impairment of taste. The integrity of the glossopharyngeal nerve may be evaluated by testing the patient's general sensation and that of taste on the posterior third of the tongue. The gag reflex can also be used to evaluate the glossphyaryngeal nerve.

Additional images

File:Brain human normal inferior view with labels en.svg, Inferior view of the human brain, with the cranial nerves labelled. File:Gray567.png, Dura mater and its processes exposed by removing part of the right half of the skull, and the brain. File:Gray719.png, Hind- and mid-brains; postero-lateral view.( File:Gray779.png, Alveolar branches of superior maxillary nerve and sphenopalatine ganglion. File:Gray792.png, Upper part of medulla spinalis and hind- and mid-brains; posterior aspect, exposed in situ. File:Gray794.png, Hypoglossal nerve, cervical plexus, and their branches.

References

Saladin, Anatomy and Physiology: The Unity of Form and Function, 6th edition

External links

* * * * () {{Authority control Cranial nerves Gustatory system Pharynx