Parotid Region And The Facial Nerve

Question 1

Give the location of the parotid gland, what secretions is it too?

Answer 1

Parotid gland lies between the zygomatic arch and the lower border of the mandible, between the SCM and the Masseter. It is

Largest salivary gland with mostly serous secretions, very little mucous.

Question 2

Give the position of the parotid duct

Answer 2

Extends anteriorly and horizontally out of the parotid gland, pierces the buccinator and then enters the mouth at around the 2nd molar region.

Question 3

What structures are embedded in the parotid gland?

Answer 3

Retromandibular vein

External carotid artery (maxillary, greater auricular and superficial temporal)

Facial nerve (but does not innervate)

Parotid lymph nodes

Question 4

Blood supply and venous drainage of the parotid gland?

Answer 4

Supplied by the maxillary, greater auricular and superficial temporal arteries of the ECA

Drained by the associated veins, S.T.Vein and Maxillary vein, which join to form retromandibular vein

Question 5

What parasympathetic innervation reaches the parotid?

Answer 5

To secrete serous secretions

Glossopharyngeal Preganglionic

Trigeminal V3 postganglionic

Question 6

Sympathetic innervation of the parotid gland?

Answer 6

Vasoconstriction and reduction in saliva

Mainly from the carotid plexus

Question 7

Describe the course of the facial nerve

Answer 7

Leaves the pons and exits skull via internal acoustic meatus into the facial canal. Here the motor and sensory root fuse and form the geniculate ganglion.

(Greater petrousal nerve branches off of Geniculate ganglion and supplies nasal and lacrimal glands)

Then exits the skull via the stylomastoid foramen and separates into its branches

Question 8

What are the branches of the facial nerve and give an area of innervation

Answer 8

Posterior auricular - behind the ear

Cervical - platysma

Marginal mandibular - lower lip and chin

Buccal - corners of mouth, upper lip

Zygomatic - inferior orbital area, upper cheek

Temporal - temple, supra-orbital

Question 9

What is Bell’s palsy and what causes it, and some symptoms / treatments

Answer 9

Unilateral paralysis of the upper and lower face

Idiopathic cause

Inability to close eye or mouth one side of mouth or facial muscles on one side

Eye drops for eyes that cannot close, or tape eye closed at night