Parotid Gland And Facial Nerve Flashcards
Which kind of secretions does the Parotid gland secrete
Serous
What are the boundaries of the parotid gland
Lies outside of the oral cavity extending between the zygomatic arch and lower border of the mandible between the SCM, external aucostic meatus and mass enter
Which kind of sheath is the parotid gland enclosed in?
Parotid sheath
Which muscle does the parotid gland pierce before entering the oral cavity near the 2nd molar
The buccinator
What is the blood supply of the parotid gland?
External carotid artery from the posterior auricular, maxillary and superficial temporal
What is the venous drainage of the parotid gland
The retromanidbualr vein ( from superficial temporal and maxillary vein)
Explain how the Parotid gland receives its blood supply
The external carotid artery passes deep and enters the parotid gland where it gives off the posterior auricular artery , then splits to give rise to terminal branches superficial temporal and maxillary artery.
Discuss the venous drainage of the parotid gland
The veins that drain the Parotid gland run with the arteries
- the superficial temporal vein and the maxillary vein.
These join to give the retromandibular vein; this eventually splits into the anteior and posteior retromandibular veins
The anterior one draining into the internal jugular vein and the external one draining into the external jugular vein
The parasympathetic innervation of the parotid gland causes the gland to produce saliva
How doe this happen
Preganglionic fibres from CN9 travel to the otic ganglion in the tympanic and lesser petrosal nerve
Postganglionic fibres from the otic ganglion pass to the auricoltemoral nerve ( CNV3) that sends branches to the parotid gland
Which nerve supplies the parotid gland?
Auriculotemporal nerve
The sympathetic innveration of the parotid gland causes vasoconstriction and some reduction in the saliva produced
How does this happen?
This sympathetic innveration is derived from the cervical plexus on the external carotid artery
If there is a paralysis of tonus in the obiculans oris (causes inferior eyelid to evert) which branch of the facial nerve is affected
This causes the inferior eyelid to evert, which is to say it falls away from the surface of the eyeball, as a result of which lacrimal fluid is not spread over the cornea, which prevents adequate lubrication, hydration, and flushing of the surface of the cornea and makes it vulnerable to ulceration. So as a result of damage to the zygomatic branch, or also the temporal branch, the cornea can be damaged and scarred, which leads to impaired vision. Lacrimal fluid will also leak onto the face, causing people to have to wipe their face, both of which may lead to skin irritation.
Patent complaining of good getting stuck in cheek which muscles have been paralysed
Buccinator and obicularis oris
What is Bell’s palsy
Term for facial paralysis there is no other obvious cause for
What are some signs that someone has bels palsy
Drooping of the mouth and inability to close eyelid on that side
Why is the eye management so important in these cases? bells. Palsy
They are unable to close their eye on the affected side - to prevent eye damage and potential impairment; drop can be prescribed or the eye taped
What is static reconstruction
After two years of facial paralysis with no improvement surgery can be carried out.
Static reconstruction involves the creation of a sling - that is attached to the side of the mouth and face to create symmetry at rest.
How can closure of eye be helped with surgery
Small gold weight can be placed onto the upper eyelid
Which nerve can be used as a graft if there is damage to the facial nerve?
The greater auricular nerve
Which arises from the ventral rami of the second and third cervical spinal nerves and gives sensation over the parotid region, the angle of the mandible the mastoid process and the auricle
What is mumps and what are common symptoms
It is a viral infection and initial symptoms include fever, headache and joint pain.
Most common and recognisable symptom is the swelling f the parotid gland - this can be painful due to the fibrous tissue capsule of the gland
