Cranial nerves-9, 10,11 By Dr Piyush,Assistant Professor, Anatomy.

1. CRANIAL NERVES
(IX, X, XI)
BY DR. PIYUSH

8. GLOSSOPHARYNGEAL NERVE
(Cranial Nerve IX)

9. INTRODUCTION
• Mixed Nerve
• Emerges from posterolateral
sulcus of Medulla Oblongata.

13. Functional component
FN COMP. NUCLEUS target origin
SVE
(BRANCHIOMOTOR)
nucleus
ambiguus
stylopharyngeus -
GVE
(SECRETOMOTOR)
Inf. Salivatory Parotid -
GSA
(SOMATOSENSORY)
spinal nucleus of
Vth nerve
-
Post 1/3rd tongue,tonsil, soft
palate & oropharynx
SVA
(GUSTATORY)
nucleus tractus
solitarius
-
Circumvalate papillae & Post
1/3rd tongue
GVA
(VISCEROSENSORY)
nucleus tractus
solitarius
-
Baro & chemoreceptors from
carotid sinus and body.

14. Course
• Arises from posterolateral sulcus of medulla in the form of 3-4 rootlets.
• In the jugular foramen combine to form nerve trunk.
• Trunk has 2 ganglion : superior & inferior
• leaves skull through intermediate compartment of Jugular foramen
• Passes between IJV and ICA
• Passes between ICA and ECA
• Deep to styloid process
• enters pharynx between superior and middle constrictor.

20. Branches
• Communicating branches with
• Superior cervical sympathetic ganglia
• superior and inferior ganglia of vagus
• facial nerve

21. To Vagus

22. • Distributing Branches: 6 sets of branches
• Tympanic branch: (secretomotor) preganglionic
parasympathetic fibres- tympanic plexus- lesser
petrosal nerve- otic ganglion- post ganglionic
fibres- via Auriculotemporal nerve - parotid gland.

25. • Carotid branch: (viscerosensory) carotid sinus and
carotid body
• Pharyngeal branches- (somatosensory) 3-4; ramify
over buccopharyngeal fascia over middle constrictor
and with vagus and superior sympathetic ganglion
branches forms the pharyngeal plexus.

26. • Muscular branch: (Branchiomotor): to stylopharyngeus
• Tonsillar branches: (somatosensory) tonsilar plexus with
middle and lesser palatine nerves
• Lingual branches: (somatosensory & gustatory) post
1/3rd tongue and valate papilla.

27. Applied
• Isolated injury is rare
• Cardiac arrest or syncope after bout of cough:
increased pressure in carotid sinus, sinus branch of IX th
nerve reflexly stimulates cardio inhibitory centres of brain
stem.

28. Vagus Nerve
(Cranial nerve X)

29. INTRODUCTION
• Mixed Nerve
• extensive distribution from head & neck to abdomen
therefore called Wandering nerve.
• Emerges from posterolateral sulcus of Medulla Oblongata
below IXth nerve.

31. Functional component
FN COMP. NUCLEUS target origin
SVE
(BRANCHIOMOTOR)
nucleus ambiguus Muscles of Pharynx & larynx
GVE
(VISCEROMOTOR)
Dorsal nucleus of
vagus
Heart, smooth muscles and
glands of respiratory tract,
alimentary trac proximal 2/3rd and
distaLal 1/3rd of transverse colon
GVA
(VISCEROSENSORY)
Dorsal nucleus of
vagus & NTS
Heart, smooth muscles and
glands of respiratory tract,
alimentary trac proximal
2/3rd and distaLal 1/3rd of
transverse colon
GSA
(SOMATOSENSORY)
upper part of spinal
nucleus of Vth nerve
External auditory canal &
tympanic membrane
SVA
(GUSTATORY)
nucleus tractus
solitarius
vallecula & pyriform fossa

33. Course
• 4 parts: Cervical; thoracic & abdominal
• Arises from posterolateral sulcus of medulla in the form of
>10 rootlets.
• In the jugular foramen combine to form nerve trunk.
• In Cervical region:
• leaves skull through intermediate compartment of
Jugular foramen
• descends in carotid sheath

39. • Between & behind IJV & CCA or ICA
• Trunk has 2 ganglion :
• superior (jugular) : pseudounipolar sensory neurons
for GSA
• inferior (nodose): pseudounipolar sensory neurons
for GVA & SVA

42. • In Thorax:
• Right vagus: passes behind the lung root and contributes in the
formation of right posterior pulmonary plexus; posterior part of
oesophageal plexus and finally enters the abdomen as posterior
vagal trunk.
• Left Vagus: passes behind the lung root and contributes in the
formation of left posterior pulmonary plexus; Anterior part of
oesophageal plexus and finally enters the abdomen as Anterior
vagal trunk.

44. • In Abdomen:
• Anterior vagal trunk:1-3 bundles; each branch divide
into hepatic and gastric branches ; supply upto
duodenum.
• Posterior vagal trunk: gastric and coeliac branches ;
supply upto transverse colon (junction of proximal 2/3rd
and distal 1/3rd)

46. Branches
• In Neck:
• from superior ganglion
• Meningeal branch: (Somatosensory) Dura of posterior
cranial fossa
• Auricular branch (Alderman’s nerve): (Somatosensory)
Auricle, floor & posterior wall of external auditory canal
and adjoining tympanic nerve

47. • From Inferior ganglion
• Pharyngeal branches
• Superior laryngeal nerve
• branches to the carotid body
• From the trunk:
• Cardiac branches
• Right recurrent laryngeal nerve

48. • In the thorax:
• Left recurrent laryngeal nerve
• Pulmonary branches
• Cardiac branches
• Oesophageal branches

49. • In the Abdomen:
• Gastric branches
• Hepatic branches
• Coeliac branches

50. Applied
• Auricular branch irritation may lead to vomitting or even
precipitate cardiac arrest.
• Recurrent laryngeal nerve injury during thyroid surgery
• Selective vagotomy for peptic ulcer.

51. Accessory Nerve
(Cranial nerve XI)

52. INTRODUCTION
• Motor Nerve
• Emerges from posterolateral sulcus of Medulla Oblongata
below vagus.
• 2 roots :
• Cranial: detached rootlet of vagus
• Spinal: C1 to C5 anterior gray horn

55. Functional component
FN COMP. NUCLEUS target origin
SE/SVE
(Somatomotor/
Branchiomotor)
Spinal nucleus of
Ascessory Nerve
(C1-C5)
Sternocleidomastoid &
Trapezius
-
SVE
(BRANCHIOMOTOR)
nucleus ambiguus Muscles of Pharynx & larynx -
GVE
(VISCEROMOTOR)
Dorsal nucleus of
vagus
Heart -

58. Course
• Cranial part:
• Rootlets arise from posterolateral sulcus of medula below the rootlets of vagus.
• In the jugular foramen combine with spinal part to form nerve trunk.
• At exit from jugular foramen leaves spinal root to combine with inferior ganglion
of vagus.
• Distributed through following branches of vagus:
• pharyngeal branch
• recurrent laryngeal
• cardiac branch

60. • Spinal part:
• Rootlets arise between anterolateral and posterolateral sulcus of C1 -C5 spinal
segments
• unite to form a single ascending spinal root of ascending nerve
• enters cranial cavity through foramen magnum.
• goes to intermediate compartment of jugular foramen
• joins the cranial root to form Acessory nerve trunk.
• At the exit of foramen, spinal part separates passes downward deep to styloid
process.
• pierces deep surface of sternocleidomastoid
• runs in posterior triangle and supplies trapezius.

64. Branches
• Communicating branches
• with C2, deep to sternocleidomastoid
• with C2 & C3 in posterior triangle
• with C3 & C4 deep to trapezius
• Distributing branches:
• To sternocleidomastoid
• To Trapezius

65. Applied
• Acessory nerve irritation causes spasm of SCM and
trapezius leading to spasmodic Torticollis.

66. Thank you