nerves.pdf

1. Glossopharyngeal, vagus, accessory and
hypoglossal nerve
Presented by:
Mr: Osman Ali Osman
MBBS University of Gezira
M.D of General Surgery
Master Degree of Human Anatomy U of G
Lecturer at Anatomy Department U of G

3. 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.

4. GLOSSOPHARYNGEAL NERVE IX.

5. LEAVES THE SKULL THROUGH THE JUGULAR FORAMEN.
THE FIST BRANCH – TYMPANIC NERNE ORIGINATES IN THE PETROSAL FOSSULA
IT HAS TWO SENSORY GANGLION: SUPERIOR (JUGULAR) AND
(PSEUDOUNIPOLAR CELLS) INFERIOR (PETROSAL)
GLOSSOPHARYNGEAL NERVE IX.

6. NUCLEI OF GLOSSOPHARYNGEAL NERVE:
ambiguus nucleus SVM
inferior salivatory nucleus GVM
nucleus of the solitary tract SVS
nucleus of the spinal trigeminal tr. GSS

8. Sensory ganglia of the glossopharyngeal nerve
PETROSAL GANGLION (INFERIOR)
JUGULAR GANGLION (SUPERIOR)
Vegetative (parasympathetic) ganglion:
OTIC GANGLION

9. GLOSSOPHARYNGEAL NERVE INNERVATES
WITH SOMATOSENSORY FIBERS: posterior 1/3 of the tongue
palatine tonsil
WITH SPECIAL VISCEROSENSORY FIBERS:
taste buds of the circumvallate papillas
WITH GENERAL VISCEROSENSORY FIBERS:
mucous membrane of the pharynx
receptors of thecarotid sinus
WITH SPECIAL VISCEROMOTOR FIBERS:
levator veli palatini muscle
stylopharyngeus muscle
constrictor muscles (pharyngeal plexus)
WITH GENERAL VISCEROMOTOR (parasympathetic) FIBERS:
parotid gland

10. BRANCHES OF GLOSSOPHARYNGEAL NERVE:
TYMPANIC NERVE GVM, GSS TYMPANIC PLEXUS LESSER PETROSAL NERVE GVM
PHARYNGEAL BRANCHES PHARYNGEAL PLEXUS SVM, GVM, GSS
NERVE FOR CAROTID SINUS GVS
TONSILLARY BRANCH GVS
LINGUAL BRANCHES SVS, GVM, GSS

12. TYMPANIC NERVE GVM, GSS TYMPANIC PLEXUS LESSER PETROSAL NERVE GVM

13. TYMPANIC PLEXUS
tympanic nerve (IX.)
communicating ramus of VII n.
caroticotympanic nerves:
(postganglionar sympathetic
fibers from the carotid plexus)

14. LESSER PETROSAL NERVE contains parasympathetic preganglionic fibers.
These fibers terminate in the otic ganglion (just beneath the oval foramen).
The postganglionis fibers join to the auriculotemporal nerve and provide the
Secretomotor innervation of the parotid gland

15. NERVE FOR CAROTID SINUS (HERING’S) GVS

16. TONSILLARY BRANCH GVS
LINGUAL BRANCHES SVS, GVM, GSS
PHARYNGEAL BRANCHES PHARYNGEAL PLEXUS SVM, GVM, GSS

18. VAGUS NERVE X.

19. X : Vagus Nerve :
Vagus nerve Nuclei & their
central connections.
It is mixed nerve, attached
lateral to olive of medulla
caudal to glosso-pharyngeal
N. in groove between olive &
inf.cerebellar peduncle.
It recevies afferent
Fs.from : 1-Receptors for
general sensation in pharynx,
larynx, tympanic membrane,
ext.acoustic meatus. 2-
Chemoreceptors in aortic
bodies and baroreceptors in
aortic arch.
3-Receptors in thoracic &
abdominal viscera.

20. Nuclei of the vagus nerve:
ambiguus nucleus SVM
dorsal nucleus of the vagus nerve GVM
lateral nucleus of ala cinerea GVS
nucleus of the solitary tract SVS
nucleus of the spinal trigeminal tr. GSS

22. Sensory ganglia of the vagus nerve
superior (jugular) ggl.
inferior (nodose) ggl
Vegetative (parasympathetic) ganglia can be found in the wall
of the viscera
intramural ganglia

23. Vagus nerve innervates
With branchialmotor SVM fibers
- levator veli palatini,
- middle constrictor of the pharynx
- inferior constrictor pharynx
- muscles of the larynx and esophagus
With somatosensory fibers
- mucous membrane of the larynx,
- mucous membrane of the inferior part of the pharynx
- epiglottic vallecules
- posterior part of the dura mater
- posterior part of the skin of the external acustic meatus

24. With special viscerosensory fibers
- the taste buds around the epiglottic vallecules
General viscerosensory and visceromotor fibers
the larynx, trachea, oesophagus, bronchi,
lungs, heart and abdominal viscera from the stomach to the
left colic flexura

25. Branches of the vagus nerve
Cranio-cervical part
1. posterior meningeal branch
2. auricular branch
3. pharyngeal
4. superior laryngeal nerve
5. superior cardiac nerves
6. recurrant laryngeal nerve:
- inferior laryngeal nerve,
- inferior cardiac nerves,
- tracheales branches,
- esophageal branches

26. Branches of the vagus nerve
Thoracic part
- cardiac branches
- bronchial branches
- pericardiac branches
- oesophageal branches
Adominal part
- branches for the viscera
- gastric plexus
- hepatic plexus
- coeliac plexus
- renal plexus

29. XI :Accessory Nerve :
Diagram of caudal medulla & rostral
spinal cord to illustrate origin and
course of vagus & accessory nerves.
It is purely motor , consists of
cranial part & spinal part.
The cranial part emerges
from lateral aspect of medulla
below vagus N. It arises from
caudal part of nucleus
ambiguus of medulla.
At the level of jugular foramen it
joins vagusN. to supply Ms. of
soft palate, pharynx & larynx.
Spinal root of accessory
arises from upper 5 cervical spinal cord
segments. It ascends to the side of medulla
to join the cranial root till the jugular F., it
separates to supply sternomastoid &
trapezius Ms.

30. Nuclei of the accessory nerve:
ambiguus nucleus SVM cranial root
motoneurons of the C1-5 SM spinal root

31. Branches of the accessory nerve
1. External branch SM
innervates the sternocleidomastoid and trapezius
2. Internal branch SVM
joins to the vagus
helps in the innervation of
the arytenoideid muscle

32. Spinal root of the accessory nerve

33. XII : Hypoglossal Nerve :
T.S.of medulla to illustrate
origin & course of hypoglossal
nerve.
It is purely motor , supplying all
extrinsic & intrinsic Ms. of tongue
except palatoglossus (by
pharyngeal plexus).
It arises from hypoglossal
nucleus in medulla ( beneath floor
of 4th V.).
It emerges from M.O. between
olive & pyramid.
It also receives coticobulbar Fs.
from contralateral motor cortex,
which subserve voluntary
movements of tongue as occur in

34. Hypoglossal nerve
Innervates: all the extrinsic and intrinsic muscles of the tongue

36. DEEP ANSA CERVICALIS

37. Motor neurone disease and lesions
of cranial nerves IX-XII :
• Occures in those over 50 years due to chronic
degeneration of cortico-bulbar tracts projecting to
nucleus ambiguus (sends motor Fs.in 9,10,11 nerves)
& hypoglossal nucleus , leading to dysphonia (difficulty
in phonation), dysphagia (difficulty in swallowing) ,
dysarthria ( difficulty in articulation) and weakness &
spasticity of tongue (pseudobulbar palsy).
• There is also degeneration of nucleus ambiguus &
hypoglossal nucleus themselves, leading to
dysphonia,dysphagia, dysarthria and weakness,
wasting & fasciculation of tongue (bulbar palsy).
• IX-XII nerves can be damaged by tumours in skull
foramina, lead to dysphonia, weakness, wasting &
fasciculation of tongue and depression of gag reflex +
wasting of sternomastoid & trapezius Ms.