Facial vii nerve

After it gives off the posterior auricular nerve, the facial nerve divides within the parotid gland into its terminal branches. The terminal branches are;

1. Temporal
2. Zygomatic
3. Buccal
4. Marginal (along the mandible)
5. Cervical

(A traditional mnemonic device for the five terminal branches of the facial nerve is, “Ten Zebras Bit My Cat”)

The facial nerve passes in a canal situated in the posterior and medial walls of the middle ear. It is not associated with the anterior wall. 

Parotid glandreceives parasympathetic innervations from glossopharyngeal nerve and not facial nerve.

Chorda tympani nerve contains preganglionic parasympathetic fibers, not parasympathetic fibers. It synapses in the submandibular ganglion.

Taste sensation from anterior two third ( fungiform , filiform papillae ) of the tongue is carried by chorda tympani nerve . Chorda tmpani nerve lies within the lingual nerve upto the infratemporal fossa. In the infratemporal fossa chorda tympani comes out of the lingual nerve and enters the pterotympanic fissure to join the facial nerve.

Blood supply of facial nerve:

Arterial supply:
In Canal: 
1. Superficial petrosal (branch of middle meningeal artery)
2. Stylomastoid (branch of posterior auricular or occipital artery)

Extracranially:
1. Stylomastoid (branch of posterior auricular or occipital artery)
2. Superficial temporal, transverse facial and tympanic (branch of ascending pharyngeal artery)

Venous drainage:
1. Venae comitantes of superficial petrosal and stylomastoid arteries.

The facial nerve innervates muscles that develop from the second branchial arch, which includes the stapedius. This muscle is important in dampening loud sounds and is located in the middle ear cavity.

• Risorius: is a dilator muscle of the lip and supplied by facial nerve.
• Zygomaticus major and minor (Dilator muscle of the lip) are supplied by the facial nerve.
• Auricularis anterior, superior and posterior are supplied by the facial nerve.
• Infact, all facial muscles (including muscle of the scalp, muscle of auricle, muscle of eyelid, muscle of nose, muscle around the mouth and muscle of the neck) are supplied by the facial nerve (motor supply). The trigeminal nerve is the chief sensory nerve of the face.

Note:

• “Anterior belly of the digastric is supplied by the nerve to mylohyoid whereas posterior belly is supplied by the facial nerve”.
• “Muscles of the mastication (lateral pterygoid, medial pterygoid, masseter and temporalis) are supplied by the mandibular division of trigeminal nerve”.

Chorda tympani is a mixed nerve which arises from the vertical segment of the facial nerve about 6mm above the stylomastoid foramen. It carries taste sensations from the anterior two third of the tongue and carries preganglionic secretomotor fibers. 

Facial nerve is a derivative of second branchial arch. Muscles of facial expression derived from it are buccinator, auricularis, frontalis, platysma, orbicularis oris and orbicularis oculi. Additional muscles supplied by it are stapedius, stylohyoid, and posterior belly of digastric.

Ref: Neuroscience for the Study of Communicative Disorders  By Subhash Chandra Bhatnagar page 279.

A , B, C i.e. Ascending pharyngeal artery, Middle meningeal artery, Stylomastoid branch of occipital artery

B i.e. Hypoglossal nerve

A i.e. Chorda tympani; B i.e. Greater petrosal nerve; C i.e. Zygomatic nerve

A. i.e. Greater petrosal nerve; C. i.e. Chorda tympani; B . i.e. N. to stapedius

C i.e. Levator palpebrae superioris

D i.e. Facial nerve

D i.e. Greater superficial petrosal nerve

D. i.e. Greater Superficial petrosal nerve

B i.e. Facial nerve

Ans. A i.e. Facial nerve supplies fungi from papillae; B i.e. Glossopharyngeal nerve supplies circumvallate papillae ; C i.e. Genioglossus is the safety muscle

–           anterior 2/3 of tongue is supplied by chorda tympani branch of facial nerveQ (carrying taste sensation) & lingual nerveQ (carrying general sensation); posterior 1/3 of tongue is supplied by glossopharyngeal nerveQ (carrying taste & general sensation both); and posterior most tongue in the region of valleculae is supplied by internal laryngeal branch of vagus nerveQ

–                  Except palatoglossus (extrinsic muscle) all muscles of tongue (i.e. all intrinsic muscles eg bilateral superior & inferior longitudinal, transverse & vertical and 3 pairs of extrinsic muscles i.e. genioglossus, hypoglossus & styloglossus/ chondroglossus) are supplied by lzypoglossal nerveQ

Hypoglossal nerve has only motor (but no sensory) supply to tongueQ, so injury to it can not lead to loss of taste or general sensationQ. Injury to hypoglossal nerve present with pure motor tongue features such as ipsilateral muscular

Greater superficial petrosal nerve: It is the first branch and arises from geniculate ganglion (i.e. first genu).

It joins the deep petrosal nerve to form vidian nerve (nerve to pterygoid canal) and carries secretomotor fibres to the lacrimal gland, nasal gland, Palate gland and pharyngeal gland.

Facial Nerve Supplies

  Facial muscles except levator palpebrae Superioris (Which is supplied by 3rd nerve).

• Posterior belly of Digastric
• Stapedius
• Auricular muscles
• Occipto Frontalis
• Platysma
• Stylohyoid

Ans: A i.e. Maxillary processes

Three processes of maxilla are:

i) The frontal process, which is directed upwards,

ii) The zygomatic process, which articulates with zygomatic bone and

iii) The alveolar process, which bears socket for upper teeth

• The digastric branch of facial nerve is short and supplies posterior belly of digastric
• The facial nerve leaves the skull by passing through the stylomastoid foramen
• Behind the neck of the mandible, facial nerve divides into its 5 terminal branches which emerge along the anterior border of parotid gland

As such, no relation of facial nerve with maxillary process has been mentioned

• Facial Nerve descends in the posterior wall of the middle ear, behind the pyramid, and emerges through the stylomastoid foramen into the neck.
• The greater petrosal nerve arises from the facial nerve at the geniculate ganglion.
• It contains secretomotor (parasympathetic) fibers to the lacrimal gland, submandibular and sublingual salivary glands, and the glands of the nose,the palate and the pharynx
• The nerve is joined by the deep petrosal nerve from the sympathetic plexus and forms the nerve of the pterygoid canal which ends in the pterygopalatine ganglion.
• The nerve to the stapedius arises from the facial nerve which supplies the muscle within the pyramid.
• The chorda tympani arises from the facial nerve just above the stylomastoid foramen. The nerve leaves the middle ear through the petrotympanic fissure and enters the infratemporal fossa, where it joins the lingual nerve. The chorda tympani contains taste fibers from the mucous membrane covering the anterior two thirds of the tongue (not the vallate papillae) and the floor of the mouth.

 Parotid gland

The Muscle Marked is Posterior Belly of Diagastric Muscle and Supplied by Facial Nerve

The Anterior Belly is supplied by Inferior Alveolar Nerve

Ans. is `a’ i.e., Facial nerve

Ans. is ‘d’ i.e., Levator palpebrae superioris

Nerve supply of face

• Each half of the face is supplied by fourteen nerves, one is motor and the rest are sensory.
• Motor supply is derived from facial (7″) nerve which supplies all facial muscles except levator palpeprae sperioris, which is supplied by sympathetic fibers and 3^rd cranial nerve.
• Eleven sensosry nerves are derived from branches of trigeminal (5^th) nerve and only two sensory are derived from great auricular nerve and transverse (anterior) cutaneous nerve of neck.

Ans;A).Facial nerve (buccal & zygomatic branch)

The muscle marked by an arrow represents Zygomaticus major.

Zygomaticus major

• It is a muscle of facial expression which draws the angle of the mouth superiorly and posteriorly to allow one to smile.
• Like all muscles of facial expression, the zygomatic major is innervated by the facial nerve (the seventh cranial nerve), more specifically, the buccal and zygomatic branches of the facial nerve.