Surface marking, origin, functional components,course,branches, areas supplied and clinical anatomy of the 10th cranial nerve i.e.Vagus

1. VAGUS NERVE
IN
HEAD AND NECK
PRESENTED BY:
DR SHAZEENA QAISER
DEPT OF CONSERVATIVE DENTISTRY AND
ENDODONTICS

2. CONTENTS:
 INTRODUCTION
 SURFACE MARKING
 GANGLIONS
 FUNCTIONAL COMPONENTS
 NUCLEI
 COURSE AND RELATIONS
 BRANCHES
 AREAS SUPPLIED IN THE HEAD AND NECK
 CLINICAL ANATOMY
 REVISION

6. INTRODUCTION
 10th cranial nerve
 So called due to its vague course through the head, neck, thorax and
the abdomen.
 Longest nerve of the autonomic nervous system in the body
 MIXED NERVE: sensory, motor and parasympathetic

7.  Fibres of the cranial root of accessory nerve are also distributed
through it.
 Primarily associated with the parasympathetic division of the
autonomic nervous system, however, it also has some sympathetic
influence through peripheral chemoreceptors.
 Associated with the derivatives of the fourth pharyngeal arch.

9. SURFACE MARKING:
 Runs along the posteromedial side of Internal Jugular Vein
 Marked by 2 points :
1. Antero-inferior part of tragus
2. Medial end of the clavicle

10. VAGUS

12. GANGLIA ASSOCIATED
SUPERIOR/JUGULAR
LIES WITHIN THE JUGULAR FORAMEN
ROUNDED
SMALLER IN SIZE
Connected to IX, XI and to
Superior Cervical Ganglion
1.MENINGEAL
2.AURICULAR
INFERIOR/GANGLION NODASUM
BELOW THE JUGULAR FORAMEN-
NEAR THE SKULL BASE
CYLINDRICAL (2.5 cm)
LARGER
Joined by cranial root of XI; connected to
XII, superior cervical ganglion
1. PHARYNGEAL
2.CAROTID
3.SUPERIOR LARYNGEAL
4.RECURRENT LARYNGEAL 5.CARDIAC

15. NUCLEI:
Within the medulla oblongata of the brainstem, there are 4 vagal nuclei, onto
which axons of the vagus nerve emerge from or converge onto:
1. NUCLEUS AMBIGUOUS (BRANCHIOMOTOR):
2. DORSAL MOTOR NUCLEUS (PARASYMAPATHETIC)
3. NUCLEUS OF TRACTUS SOLITARIS: (GUSTATORY)
4. NUCLEUS OF SPINAL TRACT OF TRIGEMINAL

16. Functional components
Specifically, the vagus nerve contains:
1. Special visceral efferent (motor) fibers.
2. General visceral efferent (motor) fibers
3. General visceral afferent (sensory) fibers
4. Special visceral afferent (sensory) fibers
5. General Somatic Afferent Fibres

18. It is responsible for not only carrying
motor signals to the organs it innervates,
but it also carries sensory information
from these organs back to the central
nervous system

19. COURSE
INTRACRANIAL
EXTRACRANIAL

21. INTRACRANIAL
Lateral aspect of
medulla;between olivary
nucleus and ICP
Nerve attached to 10
rootlets to Posterolateral
sulcus of medulla
Rootlets unite –Single trunk
Laterally across the jugular
tubercle along with IX, XI
Nerve is enclosed within the same dural sheath as the 11th
Nerve; 9th CN lies within a separate dural sheath.

23. Leaves the cranial cavity by
passing through the middle
part of jugular foramen
In the foramen, joined by
the cranial root of the
accessory nerve.

25. EXTRACRANIAL
Descends within the carotid
sheath(b/w IJV laterally and ICA
medially)
ROOT OF NECK

26. Right Vagus in front of
Right Subclavian Artery
Left Vagus between
left common carotid
and left subclavian
arteries
Enter the
Thorax
Root of the neck

28. Both the ganglia contain cell bodies
of sensory fibres of vagus nerve.
Internal branch of Accessory Nerve
unites with Vagus just above its
inferior ganglion; transfers all the
fibres to VAGUS

29. BRANCHES

30. 1.MENINGEAL
2.AURICULAR
1. PHARYNGEAL
2.CAROTID
3.SUPERIOR LARYNGEAL
4.RECURRENT LARYNGEAL
5.CARDIAC
SUPERIOR GANGLION INFERIOR GANGLION

32. 1. MENINGEAL BRANCH
Arises from
Superior Ganglion
Passes back
through Jugular
Foramen
Supplies duramater
of posterior cranial
fossa
SUPPLIES:
• Duramater of Posterior Cranial Fossa

34. 2. AURICULAR/ARNOLD’S NERVE
Arises from
Superior
Ganglion
Re-enters the
lateral portion
of the jugular
foramen via
the mastoid
canaliculus
Exits again
through the
tympanomast
oid suture of
the temporal
bone
Reaches and
supplies the
skin.
SUPPLIES:
• Concha, root of the auricle
• posterior half of the external auditory meatus
• Tympanic membrane

35. Mastoid
canaliculus
Tympanomastoid
suture

36. 3. PHARYNGEAL
LOWER PART
OF INFERIOR
GAMGLION
PASSES
BETWEEN
EXTERNAL AND
INTERNAL
CAROTID
ARTERIES
REACHES THE
MIDDLE
CONSTRICTOR
OF PHARYNX
FORMS THE
PHARYNGEAL
PLEXUS
Supplies:
• Muscles of pharynx(except the stylopharyngeus muscle)
• Muscles of soft palate (except tensor palatini muscle)

38. SUPERIOR
LARYNGEAL
EXTERNAL
LARYNGEAL
INTERNAL
LARYNGEAL
INFERIOR/
RECURRENT
LARYNGEAL
RIGHT RL
LEFT RL

41. 4.SUPERIOR LARYNGEAL NERVE
Arise from
the inferior
ganglion of
the vagus
nerve.
Moves
forwards
on the
superior
constrictor
Passes
between the
external and
internal
carotid
arteries
At the tip of
the hyoid
bone, divides
into external
and internal
branches,

43. A. EXTERNAL LARYNGEAL NERVE
Accompanies
the Superior
Thyroid
Artery
Pierces the
inferior
Constrictor
Supplies
CRICOTHYROID
Also branches to
inferior
constrictor +
pharyngeal plexus
All other intrinsic
laryngeal muscles
are innervated by
recurrent laryngeal
nerve
MOTOR

45. B. INTERNAL LARYNGEAL NERVE
Supplies the mucous membrane of larynx ABOVE the level of vocal cords
PASSES
DOWNWARDS
AND
FORWARDS
PIERCES
thyrohyoid
membrane
Enters the
larynx
SENSORY

46. 5. INFERIOR/Recurrent laryngeal nerve
Arises from
in front of
RIGHT
SUBCLAVIA
N ARTERY
Winds
backwards
below the
artery
Runs
upwards
behind
SUBCLAVIA
N AND
COMMON
CAROTID
ARTERIES
Reach the
trachea-
oesophagea
l groove;
related to
Inferior
Thyroid
Artery
Passses
deep to the
lower
border of
the
INFERIOR
CONSTRICT
OR
Enters
larynx
behind the
CRICOTHYR
OID JOINT
a. RIGHT RECURRENT LARYNGEAL

48. AREAS SUPPLIED
Right
recurrent
laryngeal
nerve
All intrinsic muscles of
larynx, except the
cricothyroid
Sensory nerves
to the larynx
below the level
of vocal cords
Cardiac branches
to the deep
cardiac plexus
Branches to trachea
and oesophagus
Inferior
constrictor

50. Arises from
Vagus in the
thorax
Loops
around
Ligamentum
arteriosum
Reaches the
tracheooeso
phagal
groove
Usually
posterior to
the inferior
thyroid
artery
Supplies:
• Similar distribution as Right RL
b. LEFT RECURRENT LARYNGEAL

51. 6. Cardiac branches
branches
off :
Superior
and
Inferior
Total 4 :Out of which
the three go to the
deep cardiac plexus
Left inferior
goes to
superficial
cardiac
plexus

53. CLINICAL ANATOMY
 The Vagus nerve is tested clinically by comparing the palatal arches on the two sides.
 On the paralysed side, there is no arching, and the uvula is pulled to the normal side.
1. Nasal regurgitation
2. Nasal twang in voice
3. Hoarseness of voice
4. Flattening of the palatal arch
5. Cadaveric position of the vocal cord
6. Dysphagia
Paralysis of vagus nerve

55.  Irritation of the auricular branch of vagus in the external ear
persistent cough, vomiting, or death (due to sudden cardiac inhibiton)
 Stimulation of the auricular branch increased appetite
 Irritation of the recurrent laryngeal nerve by enlarged lymph nodes In
children persistent cough
 Injury to recurrent laryngeal nerve hoarseness and dysphonia due
to paralysis of the right vocal cord.
 Injury to pharyngeal nerve dysphagia.

56.  Some fibres in the geniculate ganglion of facial
nerve pass into the vagus through communications
between the two nerves.
 They reach the skin of auricle through the auricular
branch of vagus.
 Sometimes a sensory ganglion may have a viral
infection and vesicles appear on the area of skin
supplied by the ganglion.-HERPES ZOSTER.
 In herpes zoster of the geniculate ganglion,
vesicles appear on the skin of auricle.

57. VAGAL NERVE STIMULATION
 A medical treatment that involves delivering electrical impulses to the
vagus
 Used as an adjunctive treatment for certain types of intractable epilepsy
and treatment-resistant depression.

58. REVISION

59. VAGUS NERVE LEAVES THE
CRANIAL CAVITY THROUGH
_____________JUGULAR FORAMEN

60. MENINGEAL BRANCH ARISES
FROM THE_______GANGLION.SUPERIO
R

61. ___________________SUPPLIES
THE MUCOUS MEMBRANE
ABOVE THE LEVEL OF THE
VOCAL CORDS
INTERNAL LARYNGEAL NERVE

62. SUPERIOR LARYNGEAL NERVE
DIVIDES INTO EXTERNAL AND
INTERNAL BRANCHES AT THE LEVEL
OF ____________HYOID BONE

63. ALL INTRINSIC MUSCLES
OF THE LARYNX EXCEPT
THE CRICOTHYROID ARE
SUPPLIED BY THE
_____________________RECURRENT LARYNGEAL
NERVE

64. REFERENCES
 B D Chaurasia’s Human Anatomy
 Gray’s Anatomy
 Anand’s Human Anatomy