anatomy of glossopharyngeal nerve

1. GOOD MORNING

3. 3
1st Olfactory.
2nd Optic.
3rd Oculomotor.
4th Trochlear.
5th Trigeminal.
6th Abducent
7th Facial.
8th Acoustic.
9th Glossopharyngeal
10th Vagus.
11th Accessory
12th Hypoglossal
Cranial nerves

4. Categorization Of Cranial Nerves
By A/Efferent Components
4
CN 1,2,8Pure sensory
CN 3,4,6,11,12Pure motor
CN 5,7,9,10mixed

5. "Glosso-" comes from the Greek
"glossa", the tongue and "pharynx" is
the Greek for throat. So the
glossopharyngeal nerve is the nerve
that serves the tongue and throat.

6. Embryology
 It is the nerve of the 3RD BRANCIAL ARCH.

7. • Motor to stylopharyngeus
• It is the nerve of ordinary sensation to the mucous
membrane of the pharynx, fauces, tonsil, carotid
body & sinus & posterior third of tongue.
• Nerve of taste to the posterior part of the tongue.
• Secretomotor to parotid gland

8. NUCLEUS OF
GLOSSOPHARYNGEAL NERVE
 NUCLEUS AMBIGUUS
 INFERIOR SALIVATORY NUCLEUS
 NUCLEUS OF TRACTUS SOLITARIUS

10. NUCLEUS AMBIGUUS
 Branchiomotor
 Special visceral efferent or Branchial efferent
 Fibers for stylopharyngeus & muscles of
pharynx , soft palate & larynx through
pharyngeal plexus.

11. INFERIOR SALIVATORY
NUCLEUS
 Parasymphathetic
 General visceral efferent nucleus
 Lies in lower part of pons
 Fibers to otic ganglion for supply of parotid gland

12. NUCLEUS OF TRACTUS
SOLITARIUS
 General visceral afferent & special visceral
afferent nuclei
 General sensations from tonsil , pharynx ,
trachea & oesophagus.
 Taste sensations from posterior third of tongue.

13. COURSE

14.  Arises from rostral part of medulla
 Passes anterolaterally to triangular
depression for aqueductus cochlea
on inferior surface of petrous
temporal bone.
 Separated from 10th & 11th nerve by inferior petrosal sinus.

15.  Exit skull through anteromedial part of jugular
foramen anterior to vagus & accessory nerve in
separate dural sheath.
 Passes between IJV & ICA
 Descends anterior to ICA deep to styloid process &
its attachements & reach to posterior border of
stylopharyngeus

16.  Curves forward on stylopharyngeus muscle & either
pierces lower fibers of superior pharyngeal
constrictor or passes between it & middle
constrictor & distribute its branches

17. GANGLIONS
 SUPERIOR GANGLION or
JUGULAR GANLION
 INFERIOR GANGLION or
PETROUS GANGLION

18.  SUPERIOR GANGLION or JUGULAR GANGLION:
-Situated on upper part of groove
- Small
- Branchless
- Regarded as detached part of inferior ganglion

19.  INFERIOR GANGLION or PETROUS GANGLION:
- Lies in notch in lower border of petrous
temporal bone.
- Larger
- Branches convey gustatory & tactile signals
from mucosa of tongue & general sensations from
oropharynx.

20. BRANCHES
 COMMUNICATING
BRANCHES
 DISTRIBUTING BRANCHES

21. COMMUNICATING
BRANCHES
Communicates with vagus , facial & symphathetic
trunk.

22. DISTRIBUTING BRANCHES
 Tympanic
 Carotid
 Pharyngeal
 Muscular
 Tonsilar
 Lingual

24.  TYMPANIC BRANCH
 Leaves inferior ganglion &
ascends to tympanic cavity
through inf. tympanic
canaliculus & forms
TYMPANIC PLEXUS
 Middle ear,
Auditory tube
Mastoid antrum
Air cells

25.  LESSER PETROSAL NERVE:
-- Receives fibers & connecting branches &
reaches to ant. Surface of petrous bone through
small opening lateral to hiatus for greater petrosal
nerve.
-- Joins otic ganglion & convey fibers to
parotid

26.  CAROTID BRANCH:
-- Arises just below jugular foramen
-- Descends on ICA to reach to
carotid body & sinus
-- Communicates with vagus &
symphathetic branches from
superoir cervical ganglion.

27. • PHARYNGEAL BRANCHES ( RAMI PHARYNGEI)
• 3 or 4 filaments which unite near the middle constrictor
with the pharyngeal branches of the vagus and sympathetic
& form the pharyngeal plexus
• Branches from this plexus perforate the muscular coat of
the pharynx and supply its muscles and mucous membrane.

28. Muscular Branch ( ramus stylopharyngeus )
Stylopharyngeus(to elevate the pharynx, as in gagging or
swallowing).

29.  TONSILLAR BRANCH( RAMI TONSILLARES)
-- Joins with lesser palatine
nerve & forms plexus.
-- Supplies :
- tonsil
- soft palate
- palatoglossal arches

30.  LINGUAL BRANCH ( RAMI LINGUALES)
-- Supplies :
- Vallate papillae & mucosa
near sulcus terminalis
- Mucosa of posterior part
of tongue & communicate
with lingual nerve.

32. APPLIED ANATOMY
 GAG REFLEX : It is possible to touch the anterior part of
the tongue with out feeling discomfort. When the
posterior part is touched, the individual gags. CN IX, CN X,
are responsible for the muscular contractions of each
side of the pharynx .

33.  Because CN 9, CN10 and CN11 pass through the jugular
foramen, tumors in this region produce multiple cranial nerve
palsies- JUGULAR FORAMEN SYNDROME
 SUPERIOR JUGULAR BULB THROMBOSIS in case of otitis media

34.  Isolated lesions of CN 9 or its nuclei are uncommon and not
associated with perceptible disability. Taste is absent on the
posterior third of the tongue and the gag reflex is absent on
the side of the lesion.
 Transient or sustained hypertension following surgical
resection of nerve indicating involvement of carotid branch
 Secretion of parotid gland reduces

35.  Glossopharyngeal neuralgia is uncommon,
-begins after the age of 40,
-occur more often in men
- common on left side.

36. -cause is unknown
 Pressure from intracranial aneurysms
 Elongated ossified stylohyoid ligament

37. • The sudden intensification of pain in:
- the back of the throat,
-the area near the tonsils,
-the back of the tongue and
- part of the ear.

38.  Pain is of a burning or stabbing character.
 These paroxysms of pain are often initiated by:
- swallowing,
-protruding the tongue,
-talking or touching the palatine tonsil.

39.  Pain paroxysms occur during eating when trigger areas are
stimulated
 Pain occurs during eating spicy & bitter food
 It is associated with:
- Syncope
- Progressive hypotension
- Bradycardia
- Arrythmia’s

40.  Diagnosis is made from clinical symptoms.
 Differential diagnosis:
- Geniculate neuralgia
- TMJD’s
- Trigeminal neuralgia
- Eagle’s syndrome

41.  TREATMENT:
 MEDICAL TREATMENT:
-Carbamazepine or Baclofen
 SURGICAL TREATMENT:
- Intracranial Rhizotomy
- Intracranial Tractotomy
- Microvascular nerve root decompression
 NEWER MODALITIES:
-Transcutaneous neural stimulation
- Acupunture

42.  The glossopharyngeal nerve is tested clinically in
the following ways:
--On tickling the posterior wall of the pharynx, there is
reflex contraction of the throat muscles. No such
contraction occurs when the ninth nerve is paralysed.
--Taste sensibility on the posterior one third of the
tongue can also be tested. It is lost in ninth nerve
lesions.

43.  REFFERENCES:
- Gray’s Textbook of Anatomy
- B D Chaurasia Textbook of Anatomy
- Burket’s Textbook of Oral Medicine , Treatment
& Planning
- Sicher & Dubruls Oral Anatomy
- Textbook of Oral & Maxillofacial Surgery by G Kruger
- Shafer’s Textbook of Oral Pathology