Glossopharyngeal, Vagus, Accessory and Hypoglossal nerves. for each nerve: Type, origin, course and relation and branches are discussed.

1. The Last 4 Cranial
Nerves
By: Khalid Mohamed Mostafa Mohamed Ibrahim
PROF. Dr. Shirley Hilal Labib El Massarany, M B Ch B, M Sc, Ph D.
Supervisor:
Professor of Human Anatomy, Faculty of Medicine, Alexandria
University

2. OUTLINE
For each nerve we will discuss:
➢Type
➢Origin
➢Course and Relation
➢Branches

3. The last 4 Cranial Nerves
IX: Glossopharyngeal nerve
X: Vagus Nerve
XI: Accessory Nerve
XII: Hypoglossal Nerve

4. IX:
GLOSSOPHARYNGEAL
NERVE

5. IX: Glosso-pharyngeal Nerve
Type: Mixed nerve, containing sensory,
parasympathetic and motor fibers.
Origin: from posterolateral sulcus of medulla.

6. Medulla

7. sulci of Medulla

8. Course and Relations of
Glossopharyngeal
Nerve

9. 1) Leaves
cranium
through
middle
compartment
of Jugular
foramen.

10. Course and
relations
2) It descends
downwards between
IJV and ICA (Upper
part of Carotid Sheath)
deep to styloid
process and muscles
attached to it.

11. Course and
relations
3) Leaves Carotid
Sheath, passing
forward with
Stylopharyngeus
m. between ICA
and ECA.

12. Course and
relations
4) Disappears deep
to Hypoglossus
muscle in the space
between the
superior and
middle constrictor
muscles.

13. Course and
relations
5) Ascends
deep to the
Hypoglossus
muscle to
reach the
tongue.

14. Termination
It ends by dividing into terminal branches supplying
the mucous membrane of the pharynx, posterior
third of tongue, and tonsils.

15. Ganglia:
It has 2 sensory ganglia in Jugular foramen.
Superior: Small and gives no branches.
Inferior: Large and gives tympanic branch.

16. Parasympathetic
pathway
to parotid
from
CN XI

17. Branches

18. Branches:
1) Meningeal Branch:
Sensory to meninges
of posterior cranial
fossa.
2) Carotid Branch:
Sensory to the Carotid
Sinus and body.

19. Branches:
3) Nerve to
Stylopharyngeus
muscle (Motor)
4) Pharyngeal Branch:
Pharyngeal Plexus
lateral to middle
constrictor muscle
(sensory to m.m. of
pharynx.)

20. Branches:
5) Tonsillar Branch
(Sensory to Tonsils)
6) Terminal Lingual
Branch:
General and
Sensory to
posterior third of
tongue

21. Branches:
7) Tympanic
Branch:
JACOBSON’S NERVE
Preganglionic
Parasympathetic to
Parotid G.

22. X: Vagus Nerve

23. X: Vagus Nerve
Type: Mixed nerve containing sensory, motor and
parasympathetic nerve fibers.
Origin: Pastor-lateral sulcus of medulla

24. Medulla

25. sulci of Medulla

26. Course and Relations

27. Course and
relations:
1) Leaves Cranium
through middle
compartment of
jugular foramen.
Two Sensory Ganglion:
Superior: inside
foramen.
Inferior: Just bellow
foramen.

28. Course and
relations:
2) Cranial root of
accessory nerve
joins inferior
ganglion of Vagus
nerve just bellow
the Jugular
foramen.

29. Course and
relations:
3) Descends
vertically into the
Carotid sheath
between and
slightly posterior to
the IJV and ICA

30. Course and
relations:
4) Descends
further vertically
to be between
the IJV and CCA
5) Crosses
Subclavian Artery
to enter the
Thorax

31. Branches of Vagus
Nerve

32. TWOBRANCHESFROMSUPERIORGANGLION
MENINGEAL BRANCH AND AURICULAR BRANCH
(SENSROY)

33. 2 branches from
inferior ganglion
1)Pharyngeal
Branch: (Motor)
Descends between
ICA and ECA to
reach Middle
Constrictor Muscle
to share in
Pharyngeal Plexus

34. 2) Superior
Laryngeal Nerve
(Mixed):
Descends DEEP TO
BOTH ICA AND ECA
Divides into
Internal br. To
Larynx
external br. To
Cricothyroid m.

35. 2 cardiac
branches:
Superior Cardiac Branch
Arises from beginning
of Vagus Nerve
Inferior Cardiac Branch:
Arises at level of root of
neck
(Both cross Subclavian
a. to reach Cardiac
Plexus)

36. Recurrent
Laryngeal Nerve:
Mixed (Sensory and
Motor)
Motor to Laryngeal
Muscles except
Cricothyroid.
Sensory to lower
half of Larynx

37. XI: Accessory Nerve

38. XI: Accessory Nerve
Type: Purely Motor
Origin:
First root: Posterolateral sulcus of Medulla
Second root: Upper 5 or 6 Cervical Segments of Spinal
Cord

39. Posterolateral sulcus of Medulla

40. sulci of Medulla

41. Cervical Segments of
Spinal Cord

42. Course and Relations of
Accessory Nerve

43. 1) Spinal root
ascends into
Foramen Magnum,
uniting with Cranial
Branch.
2) Both leave skull
through middle
compartment of
Jugular foramen

44. 3) They separate.
Cranial Branch
joins inferior
ganglion of Vagus
nerve.

45. Spinal Branch:
• Descends between IJV and
ICA
• Backwards deep to
posterior belly og digastric
muscle
• Pierces Sternomastoid
• Exits posterior border
above middle of muscle
• Across posterior triangle
of the neck
• Into Trapezius (5 cm above
clavicle)
• Ends there supplying it.

46. Branches of Accessory
Nerve

47. Cranial Accessory Nerve
Joins Vagus nerve and follows is Pharyngeal
and Laryngeal branches.

48. Spinal Accessory Nerve
Supplies Sternomastoid and Trapezius Muscles

49. XII: Hypoglossal Nerve

50. XII: Hypoglossal Nerve
Type: Motor to all intrinsic and extrinsic muscle of the tongue
except palatoglossus.
Origin: Anterolateral sulcus of Medulla

51. Course and Relations of
Hypoglossal Nerve

52. 1)Exits cranium through
Anterior Condylar
Foramen
2)Half spiral loop around
Vagus Nerve
3)Descends vertically
between IJV and ICA
4)Runs deep to Styloid
Process and Posterior
Belly of Digastric
Muscle

53. 5) Turns forwards
crossing the
following
structures
successively:
ICA
Occipital a.
ECA
Lingual a.

54. • 6) Deep to intermediate
tendon of posterior belly
of digastric
• Runs on Hyoglossus
muscle and disappears
deep into Mylohyoid
• Dips into interval
between Hyoglossus and
Genioglossus
• Breaks into terminal
branches supplying
muscles of the tongue

55. Branches of Hypoglossal
Nerve

56. Branches from Spinal
and Cranial Roots of
Accessory Nerves

57. Summary
➢All 4 CN originate in Medulla
➢CN 9 and 10 are mixed; the former to: Tongue and Tonsils and Pharynx.
the latter to: Larynx
➢CN 11 and 12 are motor; the former to: Sternomastoid and Trapezius.
the latter to: intrinsic and extrinsic muscles of tongue