Parotid gland and Facial Nerve

Question 1

What nerve innervates the parotid?

Answer 1

CNIX - glossopharyngeal

Question 2

What type of secretions does parotid have?

Answer 2

Serous

Question 3

What is the venous drainage of the parotid?

Answer 3

The retromandibular vein
Joined from superficial temporal and maxillary vein (match with arteries)
Eventually drains into IJV

Question 4

What is the arterial supply of the parotid?

Answer 4

The ECA
The terminal branches - superficial temporal and maxillary arteries

Question 5

What nerve innervates the parotid sheath and overlying skin of parotid?

Answer 5

Auriculotemporal nerve (branch of CNV3)

Question 6

What is the parasympathetic innervation to the parotid? (preganglionic and postganglionic fibres)

Answer 6

Preganglionic fibres from CNIX travel to otic ganglion in tympanic and lesser petrosal nerve.
Postganglionic fibres from otic ganglion pass to auriculotemporal nerve that sends branches to parotid.

Question 7

What is the sympathetic innervation of the parotid?

Answer 7

External carotid plexus

Question 8

Where does the facial nerve exit the skull?

Answer 8

Stylomastoid foramen

Question 9

What does the temporal branch of the facial nerve supply?

Answer 9

Muscles of the temple, forehead and supra-orbital area.

Question 10

What does the zygomatic branch of CNVII supply?

Answer 10

Muscles of infra-orbital area, the lateral nasal area and the upper lip.
Orbicularis oris

Question 11

What does the buccal branch of CNVII supply?

Answer 11

Muscles of the cheek, upper lip and corner of mouth

Question 12

What does the mandibular branch of CNVII supply?

Answer 12

Muscles of the lower lip and chin

Question 13

Cervical branch of CNVII supply?

Answer 13

Platysma

Question 14

Describe the symptoms of Bell’s Palsy

Answer 14

Unilateral paralysis of the facial muscles
Cannot close the eye fully (or at all) - need to protect the eye to prevent eye damage or vision impairment.
Drooping of side of face

Question 15

Where does the parotid duct travel?

Answer 15

Travels across the parotid gland the pierces the buccinator. Opening of the duct is at the upper 2nd molar.

Question 16

Where is the parotid region?

Answer 16

Covers the area anterior to ears and inferior to zygomatic arch

Question 17

Where is the parotid gland located?

Answer 17

In the “parotid bed” - antero-inferior to external acoustic meatus.

Question 18

What is another name for parotid duct?

Answer 18

Stensens duct

Question 19

Describe the infratemporal portion of CNVII

Answer 19

Exits pons as 2 roots - motor and (sensory and parasympathetic)
Enter internal acoustic meatus and then facial canal
2 roots fuse and become geniculate ganglion
Greater petrosal nerve branches at this point
Nerve to stapedius
Chorda tympani
Exits through stylomastoid foramen

Question 20

Describe extratemporal portion of CNVII

Answer 20

Exits skull at stylomastoid foramen
Gives posterior auricular and digastric branch.
Enters the parotid

Question 21

What is a common complication of parotid surgery or parotidectomy (removal of parotid gland)?

Answer 21

Facial paralysis
Facial nerve injury or bruising

Question 22

What can happen as a result of damage to the zygomatic branch of CNVII?

Answer 22

Paralysis of orbicularis oculi.
Causes inferior eyelid to fall away from eye.
Lacrimal fluid is the not spread across cornea and eye can be scarred or vulnerable to ulceration.

Question 23

What are some symptpoms of Bell’s palsy?

Answer 23

Unilateral paralysis of upper and lower parts of the face

Question 24

How can Bell’s palsy be treated?

Answer 24

Steroids (do not always help)
Sometimes anti-viral prescribed
EYE TREATMENT - eyedrops and patch
Surgical

Question 25

What nerve can be used for a graft for the facial nerve if damage is likely to occur?

Answer 25

Greater auricular