Notes on Facial Nerve

  >   Rahul's Noteblog   >   Notes on Neurology   >   Cranial Nerves and Parasympathetic Ganglia   >   Notes on Facial Nerve

FACIAL NERVE

Type:

Mixed motory and sensory (N. intermedius) (general visceral efferent, general somatic afferent, special visceral afferent and efferent).

Roots:

1. Motor component.

2. Sensory component (N. intermedius).

Course of Nerve:

Internal acoustic meatus, petrous part of temporal bone, facial canal (geniculate ganglion) and exits the skull via the stylomastoid foramen. Within the parotid gland splits into two main divisions:

a. Temporo-facial division.

b. Cervico-facial division.

Terminates in 5 peripheral branches (temporal, zygomatic, buccal, mandibular, and cervical.

Supplies:

Muscles of facial expression, scalp and auricle muscles, buccinator, platysma, stapedius, stylohyoid muscle and posterior digastric belly. Special sensory supply anterior two-thirds of tongue (taste fibres via chorda tympani nerve), soft palate taste fibres (via palatine and greater petrosal nerves and secretomotor parasympathetic fibres to the submandibular, sublingual, and lacrimal glands and glands of the nasal and palatine mucosa.

Nuclei:

1. Facial motor nucleus (PONS).

2. Nucleus solitarius (medulla - sensory taste fibres).

3. Geniculate ganglion (sensory).

Branches:

Within Facial Canal:

1. Greater (superficial) petrosal nerve - contains N. intermedius fibres - taste fibres.

2. Communicating (with lesser superficial petrosal nerve) and deep petrosal nerve (sympathetic fibres around the internal carotid artery) to form the nerve of the pterygoid canal that enters the pterygopalatine ganglion.

3. External petrosal.

4. Nerve to stapedius (dampens auditory signal).

5. Chorda tympani (passes in inner ear between handle of malleus and long process of the incus. Supplies anterior two-thirds of the tongue with taste fibres and secreto-motor fibres (via the submandibular ganglion) to the submandibular, sublingual and buccal glands (parasympathetic). Taste fibres are carried by the lingual nerve to the tongue.

At Exit from Stylo-mastoid foramen:

1. Posterior auricular (supplies auricularis posterior and posterior belly of occipito-frontalis).

2. Stylo-hyoid.

3. Digastric (posterior belly).

On Face via Parotid Plexus:

1. Temporal.

2. Zygomatic.

3. Buccal.

4. Mandibular.

5. Cervical.

Nervus Intermedius:

Often termed sensory root of the facial nerve.

Origin:

Secretomotor and sensory.

1. Secretomotor (para-sympathetic): floor of mouth, lacrimal gland, palate, nasal cavity, nasopharynx and paranasal sinuses.

2. Sensory (taste): cell bodies in the facial geniculate ganglion; nucleus tractus solitarius.

Branches:

1. Greater (superficial) petrosal nerve (secreto-motor to palate and taste fibres on the oral surface of the palate). Joined by deep petrosal nerve to form the nerve of the pterygoid canal which enters the pterygo-palatine ganglion.

2. Tympanic branches.

3. Chorda tympani (secreto-motor for the glands in the floor of the mouth and taste anterior two-thirds of tongue.

Further Topics on Cranial Nerves:

1. Introduction to Cranial Nerves
2. Notes on Olfactory Nerve CN 1
3. Notes on Optic Nerve CN 2
4. Notes on Oculomotor Nerve CN 3
5. Notes on Trochlear Nerve CN 4
6. Notes on Trigeminal Nerve CN 5
7. Notes on Abducens Nerve CN 6
8. Notes on Facial Nerve CN 7
9. Notes on Vestibulocochlear Nerve CN 8
10. Notes on Glossopharyngeal Nerve CN 9
11. Notes on Vagus Nerve CN 10
12. Notes on Accessory Nerve CN 11
13. Notes on Hypoglossal Nerve CN 12
14. Summary of Cranial Nerve Nuclei
15. Summary of Cranial Nerve Functions

Additional Reading:

Basic Neurology

1. Peripheral Nervous System
2. Central Nervous System
3. The Ventricular System
4. The Spinal Cord
5. The Brain Stem
6. The Cerebellum
7. Visual Pathways
8. Diencephalon
9. Basal Ganglia
10. Cerebral Cortex
11. Sleep Disorders
12. Autonomic Nervous System
13. Cranial Nerves and Parasympathetic Ganglia
14. Cells of the Nervous System
15. Cerebrospinal fluid
16. Additional short notes on Cerebrum
17. Functions and Diseases of Cerebrum
18. Subcortical Grey Matter
19. Notes on The Spinal Cord
20. Regulation of Heart Rate by Autonomic Nervous System
21. Action Potentials, Axon Conduction, and Neuromuscular Junction
22. Types of Seizures
23. What is a Cough Reflex?
24. Notes on Congenital Prosopagnosia
25. Findings in Parkinson's Disease
26. Types of Heat Strokes
27. Types of Strokes
28. What is Benign Intracranial Hypertension?
29. What is Cauda Equina Syndrome?
30. Cranial Nerve Locations in Brain Stem
31. What is a Cluster Headache?
32. What is a Subarachnoid Hemorrhage?
33. What is a Tension Headache?

Neurology Videos

1. Video of Neurology Examination in a Clinical Setting

Medical Images

Useful Medical Images & Diagrams (link opens in a new window)

Related Topics

1. Nervous System Disorders
2. Histology of Nervous Tissue
3. Cranial Nerve Reflexes
4. Motor System Examination

Random Pages:

The Existence of Matter Pictures of old Kuwaiti Dinars
Video of me playing Unknown Easy Blues Piano Notes on Muscle Tissue
Video of Musculoskeletal Examination in a Clinical Setting Notes on Enterococcus
Notes on Citric Acid Cycle and Glyoxylate Cycle Notes on Descriptive Statistics
Differentiation and Anatomy of a Blastocyst Diagram of Gastric Blood Supply
Notes on Basic Gastrointestinal Physiology Why did I become a doctor?
Review of the HMT Janata Hindi Dial wrist watch What is an ELEK`s Test?
Why did I decide to become a doctor? Medical School Admissions Essay Video: Titanic Piano Theme: The Portrait
Corporate Failure: The Enron Case My Experience during the Iraqi Invasion of Kuwait
USMLE Blood Lab Values Regulation of Heart Rate by Autonomic Nervous System
Images of Antibodies Video of me playing Yanni`s "Nightingale"
Notes on Respiratory System Differentiation and Anatomy of a Blastocyst
Notes on Cell Components Notes on Nervous Tissue
Voices from Hell: My Experience in Mussoorie, India Video of Cardiology Examination in a Clinical Setting

Please Do Not Reproduce This Page

This page is written by Rahul Gladwin. Please do not duplicate the contents of this page in whole or part, in any form, without prior written permission.