The glossopharyngeal nerve (CN IX) emerges from the medulla and exits the skull through the jugular foramen. It has sensory and motor functions. Sensory fibers innervate the posterior third of the tongue, tonsils, pharynx, and middle ear. Motor fibers innervate the stylopharyngeus muscle. Parasympathetic fibers pass to the otic ganglion to ultimately innervate the parotid gland and stimulate saliva secretion.

1. The Glossopharyngeal Nerve
PLAY
Figure 14.27

2. Glossopharyngeal
• Fibers emerge from the medulla, leave the skull
via the jugular foramen, and run to the throat
• Nerve IX is a mixed nerve with motor and sensory
functions
• Motor – innervates part of the tongue and
pharynx, and provides motor fibers to the parotid
salivary gland
• Sensory – fibers conduct taste and general
sensory impulses from the tongue and pharynx

3. Glossopharyngeal nerve
• Leave the skull through jugular
foramen
• Passes forwards between
internal jugular vein and
external carotid artery.
• Deep to styloid process.
• Between external and internal
carotid arteries at posterior
border of stylopharyngeus then
lateral to it.
• Reaches the pharynx by passing
between middle and inferior
constrictor, deep to hyoglossus,
where it breaks into terminal
branches.
•

4. Glossopharyngeal Nerve
• A mixed nerve (sensory,
motor, parasympathetic)
• Emerges from the ventral
surface of the medulla
oblongata
• Runs laterally in the
posterior cranial fossa
• Leaves the skull by passing
through the central part of
the jugular foramen
• Has superior and inferior
ganglia, that are located
within the jugular foramen.

5. • At its exit from the skull, it
passes forward between the
internal jugular vein and
internal carotid artery,
within the carotid sheath
• Descends to the lower
border of the
stylopharyngeus muscle.
• Then curves forward around
the stylopharyngeus and
• Passes through the gap
between the superior and
middle constrictor muscles
of the pharynx

6. • Passes under cover of
the hyoglossus muscle
• Distributed to the:
 Palatine tonsil
 Mucous membrane of
the fauces and base
of the tongue,
 Mucous glands of the
mouth P
F
T
PT

7. Gloosopharyngeal nerve
• jf--jugular foramen
• sg--superior ganglion
• ig--inferior ganglion
• tp--tympanic plexus
• lpn--lesser petrosal nerve
• fo--foramen ovale
• og--otic ganglion
• pg--parotid gland
• sp--nerve to
stylopharyngeus muscle
• pb--pharyngeal branch
• ncbcs--nerve to carotid
body carotid sinus
• Red solid -- motor
• Red dotted --
parasympathetic
• Yellow -- sensory (afferent)

8. Glossopharyngeal nerve
• Ganglia
• Superior ganglion
small, with no
branches.
• Inferior ganglion, large
carries general
sensations from
pharynx, soft palate
and fauces.

9. Nerve IX: Glossopharyngeal

10. Detail on Glossopharyngeal (IX) Function:
•Motor to stylopharyngeus muscle.
•Parasympathetic secretomotor fibers to parotid
gland.
•Sensory to pharynx, tonsils, and posterior 1/3 of
tongue.
•Taste fibers for posterior 1/3 of tongue.

11. Glossopharyngeal Nerve (IX)
• Innervates structures of the tongue and
pharynx
Table 14.3 (9 of 12)
Facial nerve (VII)
Vestibulocochlear
nerve (VIII)
Glossopharyngeal
nerve (IX)
Vagus nerve (X)
Accessory nerve (XI)
Hypoglossal nerve (XII)

12. COURSE
• It arises from the
medulla ,and then
passes through the
Jugular foramen of
the skull ,between
the IJV and the ICA.
• It is accompanied by
Cranial nerves X and
XI.
• It follows the ICA.

13. • It passes under the Styloid process ,and
then into the pharynx ,where it lies over
the Stylopharyngeus muscle and the
middle pharyngeal constrictor muscle.
• It then passes undercover of the of the
Hyoglossus muscle ,and is then
distributed to the Palatine tonsil,and
mucus memb of fauces,base of tongue
,and mucus glands of the mouth.

14. 1. The glossopharyngeal nerve arises by 4-5 rootlets from the
posterolateral sulcus of medulla.
2. It leaves the skull through the jugular foramen.
3. While it lies in jugular foramen it has 2 small sensory ganglia (superior
and inferior).
4. It descends downwards inside the upper carotid sheath superficial to
vagus nerve and between IJV & ICA lying deep to the styloid process
and muscle attached to it.
5. Then it leaves the carotid sheath and passes forwards with
stylopharyngeus muscle between the ICA & ECA.
6. Ascends deep to hyoglossus to reach the tongue.
Termination: it ends into terminal branches supplying the mucous
membranes of pharynx, tonsil and the posterior 1/3 of tongue.
Course of Glossopharyngeal Nerve

15. IX : Glossopharyngeal Nerve :
Glossopharyngeal nerve nuclei & their
central connections
It is a mixed N. ,attached
lateral to olive in rostral
medulla and leaves the skull
through jugular foramen.
It receives afferent Fs. From :
1-Receptors of general sensation
in pharynx, post.1/3 of tongue,
eustachian tube & middle ear.
2- Taste buds of pharynx &
post.1/3 of tongue.
3- Chemoreceptors in carotid
body & Baroreceptors in the
carotid sinus.

16. 1. Meningeal branch (sensory):
 Arises from the intracranial part of the glossopharyngeal
nerve.
 Sensory nerve supplies meninges of posterior cranial
fossa.
Branches of the Glossopharyngeal Nerve

17. 2. Tympanic branch (Jacobson's Nerve- parasympathetic nerve):
 Preganglionic parasympathetic nerve to parotid gland.
 Arises from the inferior ganglion of the glossopharyngeal nerve in
the jugular fossa.
Course of the tympanic nerve:
 It passes through the tympanic canaliculus.
 It reaches the middle ear cavity where it breaks to form the
tympanic plexus.
 Lesser superficial petrosal nerve arises from the tympanic plexus
and reaches the middle cranial fossa.
 Then lesser superficial petrosal nerve passes through the foramen
ovale to reach infratemporal fossa to relay in the otic ganglion.
 The postganglionic fibers joint the auriculotemporal to supply the
parotid gland.
Branches of the Glossopharyngeal Nerve

18. 3. Carotid branch (sensory): sensory nerve to the
carotid sinus and carotid body.
4. Nerve to stylopharyngeus muscle (motor):
motor nerve to stylopharyngeus muscle.
Branches of the Glossopharyngeal Nerve

19. 5. Pharyngeal branches (sensory): they enter the
formation of the pharyngeal plexus and supplies
the mucous membrane of pharynx.
The pharyngeal plexus receives also:
a. Motor fibers (the pharyngeal branches of
vagus nerve).
b. Sympathetic fibers(the pharyngeal branches
of the superior cervical ganglion)
Branches of the Glossopharyngeal Nerve

20. 6. Tonsillar branches (sensory): to the palatine tonsil.
7. Lingual branches (sensory): terminal branches to
mucous membrane of the posterior 1/3 rd of the tongue
(taste and general sensation).
Branches of the Glossopharyngeal Nerve

21. Branches
• Tympanic branch: Passes to the
tympanic plexus in the middle ear
and:
 Supplies sensory fibers to the
plexus
 Carries preganglionic
parasympathetic fibers, that
leave the plexus as lesser
petrosal nerve and synapse in
the otic ganglion
• Carotid branch: carries sensory
fibers from the carotid sinus &
carotid body
• Muscular branch to the
stylopharyngeus muscle

22. Branches cont’d
• Lingual branch: passes to the
posterior third of the tongue
and the circumvellate
papillae
• Pharyngeal branches: carry
sensory fibers to the
pharyngeal plexus, which
supplies the mucous
membrane of the pharynx,
tonsil and soft palate
• Communicates with the:
• Vagus & facial nerves
• Superior cervical ganglion
of the sympathetic chain

23. Branches.
• Of communications:
• Inferior ganglion and
• superior cervical
sympathetic ganglion.
• Superior ganglion and
auricular branch of
vagus.
• Its trunk and facial nerve
at stylomastoid foramen

24. Branches.
• Of distribution:
• Tympanic.
• Stylopharyngeus.
• Pharyngeal.
• Tonsillar.
• Lingual .

25. IMPORTANT BRANCHES
• The Tympanic br.to the tympanic plexus in the
middle ear.
• Lesser petrosal N arises from this plexus and
passes to the parotid gland.
• Carotid br,which carries sensory fibres .
• Nerve to the Stylopharyngeus
• Pharyngeal brs
• Lingual br ,which supplies the post 1/3rd of the
tongue.

26. • C/C
The general sensory component mediates the
afferent limb of pharyngeal reflex in which
touching the back of the pharynx elicits the
gag reflex . This is used to test the
Glossopharyngeal nerve clinically.

27. IX : Glossopharyngeal Nerve Fibres :
Glossopharyngeal nerve nuclei &
their central connections. Red= motor,
brown=parasymp.,blue=sensory
1-Afferent Fs. for general
sensation : end in trigeminal
sensory nucleus.
-Fibres carrying touch sensation
from back of tongue +pharynx
are important for mediating gag
reflex, through connection with
nucleus ambiguus & hypoglossal
nucleus.
2-Afferent visceral (chemo-&
baroreceptors) & taste Fs. :
end in nucleus solitarius of
medulla.

28. IX : Glossopharyngeal Nerve Fibres :
Glossopharyngeal nerve nuclei &
their central connections. Red= motor,
brown=parasymp.,blue=sensory
3-Efferent motor Fibres :
arises from its motor nucleus in the
rostral part of nucleus ambiguus of
medulla to supply stylopharyngeus
involved in swallowing.
4-Efferent Parasympathetic
Fibres : arises from inferior
salivary nucleus of rostral medulla
to synapse in otic ganglion, then via
post-ganglionic Fs.innervate parotid
gland.

30. 1. Nucleus ambiguus (SVE)
• Branchial motor to stylopharyngeus
2. Inferior salivary nucleus (GVE)
• to parotid gland (via otic ganglion)

31. 3. Spinal trigeminal nucleus
• Somatic sensory from outer ear (superior
ganglion of IX)
4. Nucleus of the solitary tract
• Visceral sensory from carotid body and sinus,
mucosa of pharynx, posterior tongue, middle ear
(inferior ganglion of IX)
• Visceral sensory from taste buds on posterior third
of tongue (inferior ganglion of IX)

32. Glossopharyngeal nerve (Ⅸ)
Components of fibers
• SVE fibers: originate from nucleus ambiguus, and supply
stylopharygeus
• GVE fibers: arise from inferior salivatory nucleus and ralyed in otic
ganglion, the postganglionic fibers supply parotid gland
• SVA fibers: arise from the cells of inferior ganglion, the central
processes of these cells terminate in nucleus of solitary tract, the
peripheral processes supply the taste buds on posterior third of
tongue
• GVA fibers: visceral sensation from mucosa of posterior third of
tongue, pharynx, auditory tube and tympanic cavity, carotid sinus
and glomus, and end by synapsing with cells of nucleus of solitary
tract
• GSA fibers: sensation from skin of posterior surface of auricle and

34. Course: leaves the skull via jugular foramen
Branches
• Lingual branches : to taste buds and mucosa of posterior third of tongue
• Pharyngeal branches : take part in forming the pharyngeal plexus
• Tympanic nerve : GVE fibers via tympanic and lesser petrosal nerves to
otic ganglion, with postganglionic fibers via auriculotemporal (Ⅴ3) to
parotid gland
• Carotid sinus branch : innervations to both carotid sinus and glomus
• Others: tonsillar and stylophayngeal branches
Otic ganglion: situated just below foramen ovale

38. Glossopharyngeal Nerve
• Modalities:
SVM:
From:
Nucleus ambiguous.
To:
Stylopharyngeus.

39. Glossopharyngeal Nerve
• Modalities:
GVS:
From:
Carotid body.
Carotid sinus.

41. Glossopharyngeal Nerve
• Modalities:
GVM:
Preganglionics:
From:
Inferior salivatory nucleus.
To:
Otic ganglion.
Postganglionics:
To:
Parotid gland.

42. Glossopharyngeal Nerve
• Modalities:
GSS:
From:
Posterior 1/3 of tongue.
External ear.
Middle ear cavity.

43. Glossopharyngeal Nerve
• Modalities:
SVS:
From:
Posterior 1/3 of tongue (taste).

44. Functions
• Receives general sensory fibers from the posterior
⅓ of the tongue, tonsil, pharynx, middle ear and
carotid sinus.
• Receives special sensory (taste) fibers from the
posterior ⅓ of the tongue and the circumvellate
papillae
• Supplies parasympathetic fibres to the parotid
gland via the otic ganglion
• Supplies motor fibers to stylopharygeus muscle
• Contributes sensory fibers to the pharyngeal plexus

45. Table 13.2

46. Cranial nerves
Glossopharyngeal Nerve (CN IX)
Functions: Sensory (general somatic afferent, special visceral afferent, general visceral afferent), motor (special
visceral efferent), and parasympathetic (general visceral efferent) for derivatives of the 3rd pharyngeal arch.
Nuclei: Four nuclei in the medulla send or receive fibers via CN IX: two motor and two sensory. Three of these
nuclei are shared with CN X.
The glossopharyngeal nerve (CN IX) emerges from the lateral aspect of the medulla and passes anterolaterally to
leave the cranium through the anterior aspect of the jugular. At this foramen are superior and inferior (sensory)
ganglia, which contain the pseudounipolar cell bodies for the afferent components of the nerve. CN IX follows the
stylopharyngeus, the only muscle the nerve supplies, and passes between the superior and the middle constrictor
muscles of the pharynx to reach the oropharynx and tongue. It contributes sensory fibers to the pharyngeal plexus
of nerves.
CN IX is afferent from the tongue and pharynx (hence its name) and efferent to the stylopharyngeus and parotid
gland.
Branchial Motor Motor fibers pass to one muscle, the stylopharyngeus, derived from the 3rd pharyngeal arch.
Parasympathetic (Visceral Motor)
Following a circuitous route initially involving the tympanic nerve, presynaptic parasympathetic fibers are provided
to the otic ganglion for innervation of the parotid gland. The otic ganglion is associated with the mandibular nerve
(CN V3), branches of which convey the postsynaptic parasympathetic fibers to the parotid gland .
Sensory (General Sensory)
The general sensory branches of CN IX are as follows : The tympanic nerve. The carotid sinus nerve to the carotid
sinus, a baro- (presso) receptor sensitive to changes in blood pressure, and the carotid body, a chemoreceptor
sensitive to blood gas (oxygen and carbon dioxide levels).
The pharyngeal, tonsillar, and lingual nerves to the mucosa of the oropharynx and isthmus of the fauces (L. throat),
including palatine tonsil, soft palate, and posterior third of the tongue. In addition to general sensation (touch, pain,
temperature), tactile (actual or threatened) stimuli determined to be unusual or unpleasant here may evoke the gag
reflex or even vomiting.
Taste (Special Sensory) Taste fibers are conveyed from the posterior third of the tongue to the sensory ganglia.

47. Lesion of the Glossopharyngeal Nerve:
1. Loss of taste and general sensation from the posterior
1/3 of the tongue.
2. Loss of sensation in the pharynx.
3. Some pharyngeal weakness.
4. Loss of salivation from the parotid gland.

48. Glossopharyngeal Nerve Lesions
• Glossopharyngeal nerve lesions
produce:
 Difficulty in swallowing
 Loss of general sensation over the
posterior one-third of the tongue,
palate, and pharynx
 Loss of taste sensation over the
posterior one-third of the tongue
and palate
 Dysfunction of the parotid gland
 Loss of the gag reflex

49.  The glossopharyngeal nerve is a mixed nerve containing:
a. Sensory fibers.
b. Parasympathetic fibers
c. Motor fibers.
 It is more important as sensory than as a motor nerve.
Origin: from posterolateral sulcus of medulla.
The Glossopharyngeal Nerve (IX)

50. It has three nuclei:
1. The upper part of nucleus ambiguous: it lies in the medulla (motor
function).
2. The inferior salivary nucleus: it lies in the medulla (parasympathetic
function).
3. The solitary nucleus: it lies in the medulla (sensory function).
Nuclei of Glossopharyngeal Nerve

57. IX: GLOSSOPHARYNGEAL
• carries information from the head and neck to the
brainstem.
• Information about blood pressure (baroreceptors)

58. CN IX: glossopharyngeal nerve

59. CN IX and X