INTRODUCTION- GLASSOPHARYNGEAL NUCLEI-FUNCTIONAL COMPONENT-COURSE AND DISTRIBUTION-TERMINATION -BRANCHES-PARASYMPATHETIC COMPONENT-CLINICAL ANATOMY-REFERENCES

1. GLASSOPHARYNGEAL NERVE
BY
DR .M.MD. MUSTAFA SHARIFF
SENIOR LECTURER
SRMDCH

2. GLASSOPHARYNGEAL NERVE
 The glassopharyngeal nerve is a mixed cranial nerve.
 Embryologically , it is the nerve of the third pharyngeal
arch.

3. GLASSOPHARYNGEAL NUCLEI
Nuclei are situated within the medulla oblongata.
(a) Motor nucleus - Nucleus ambiguus.
(b) Sensory nucleus - Nucleus of tractus solitarius.
(c) Parasympathetic nucleus - inferior salivatory
nucleus.

5. FUNCTIONAL COMPONENT
 Special visceral efferent fibres arise from nucleus
ambiguus and supply only one muscle, the
stylopharyngeus, the muscle of third pharyngeal arch.
 General visceral efferent fibers arise from inferior
salivatory nucleus and relay in the otic ganglion.
 The post ganglionic fibres arising from ganglion
supply the parotid gland via auriculotemporal nerve (a
branch of mandibular nerve).

6. General visceral afferent fibres :
 These fibres lie in the superior ganglion of the
glossopharyngeal nerve.
 The peripheral processes of these cells carry general
sensation (touch, pain, & temperature).
 From posterior one-third of the tongue, pharynx, carotid
body and carotid sinus to the ganglion.
 The central processes carry these sensation to the
spinal nucleus of the trigeminal nerve.

7.  Special visceral afferent fibres have their cell bodies in
the inferior ganglion of the glossopharyngeal nerve.
 The peripheral processes of these cells carry taste
sensation from the posterior one third of the tongue and
circumvallate papillae to the ganglion.
 The central processes convey these impulse to the
nucleus of tractus solitarius.

8. COURSE AND DISTRIBUTION

9.  The 8-10 rootlets of the nerve emerges through the
posterolateral sulcus of the medulla oblongata.
 They emerge superior to the vagus and accessory nerves.
 All the roots unite to form the nerve.
 It passes through the jugular foramen and leaves the cranial
cavity.
 At jugular foramen , it has a pair of ganglia namely superior
and inferior ganglia.

10.  It descends between the internal carotid artery and internal
jugular vein.
 It then passes forwards between internal and external
carotid arteries.
 It is situated deep to the styloid process.
 It hooks around the stylopharyngeus muscle.
 It then passes in the interval between the superior and
middle constrictor of the pharynx.

11. TERMINATION
 It terminates by supplying the posterior 1/3rd of the
tongue,tonsil,pharynx and gland of the mouth.

12. BRANCHES
1. Tympanic branch (Jacobson's nerve) is carrying
parasympathetic fibres to supply the parotid gland.
2. Carotid sinus nerve (Nerve of Herring) to supply the carotid
sinus and carotid body.
3. Pharyngeal branches 3-4 branches join the pharyngeal
plexus.
4. Muscular branch supply to stylopharyngeus.

13. 5. Tonislar branch to supply the palatine tonsil.
6. Lingual branch to supply posterior 1/3rd of the tongue both
ordinary sensation and taste.

14. PARASYMPATHETIC COMPONENT
INFERIOR SALIVATORY NUCLEUS
GLOSSOPHARYNGEAL NERVE
TYMPANIC PLEXUS
LESSER SUPERFICIAL PETROSAL NERVE
OTIC GANGLION
AURICULOTEMPORAL NERVE
PAROTID GLAND

15. CLINICAL ANATOMY
Lesions of the glossopharyngeal nerve causes,
 loss of Gag reflex.
 Loss of taste in posterior 1/3rd of the tongue.
 Loss of sensation on the tonsil & pharynx.
 Deviation of the uvula.
 Tachycardia

16. REFERENCES
 EXAM-ORINTED ANATOMY SHOUKAT N.KAZI
 HEAD & NECK AK DATTA 5TH EDITION
 GRAYS ANATOMY STUDENTS EDITION
 CLINCAL ANATOMY SNELL 8TH EDITION
 CLINICAL ANATOMY MOORE 5TH EDITION
 HEAD & NECK BD CHAURASIA’S 4TH EDITION
 HEAD & NECK DR.AS.MONI