Facial nerve anatomy

facial nerve anatomy

1. Facial nerve anatomy

2. The facial nerve is the seventh VII cranial nerve. It emerges on anterior surface of hindbrain between the pons and the medulla

3. Embryology The facial nerve developmentally derived from the 2nd pharyngeal arch (branchial arch) which is also called the hyoid arch.

4. Motor division  from basal plate of the embryonic pons Sensory division  from cranial neural crest The facial nerve supplies motor and sensory innervation to muscles formed by 2nd pharyngeal arch : Muscles of facial expression Posterior belly of the digastric Stylohyoid Stapedius

5. The anterior 2/3 of tongue are derived from 1 st pharyngeal arch, which gives rise to CN V.. Nerve fibers for taste are supplied by the chorda tympani branch of facial nerve via special visceral afferent fibers.

6. Structure The path of the facial nerve can be divided into 6 segment : intracranial (cisternal) segment meatal segment (brainstem to internal auditory canal) labyrinthine segment tympanic segment mastoid segment extra temporal segment

7. Course

8. Intracranial branches

9. Extra cranial branches

10. Blood supply Labyrinthine artery : a branch of anterior inferior cerebellar artery , supplies meatal segment. Superficial petrosal artery: a branch of middle miningeal artery which passes retrogradely along greater superficial petrosal nerve. stylomastoid artery : branch of occipital artery, which passes retrogradely into stylomastoid foramen.

11. Functions Facial expressions

12. 2. Facial sensation : small amount of afferent innervation to the oropharynx. small amount of cutaneous sensation carried by the nervus intermedius from the skin in and around the auricle. receives taste sensations from the anterior 2/3 of the tongue via the chorda tympani.

13. 3. Parasympathetic :

14. * facial nerve also functions as the efferent limb of the corneal reflex.

15. Functional components

16. Examination a. Voluntary facial movements

17. b. Taste test

18. c. Corneal reflex

19. Bell’s Palsy

20. Ramsay Hunt Syndrome :

21. Upper & lower motor neuron lesion

22. Any questions ?

23. Thank U ^_^

24. References : https://en.wikipedia.org/wiki/Facial_nerve Clinical Anatomy 9 th Edit _ Snell

25. Done by : Ola Qatu Submit to : Dr.Kareem