Face Flashcards
What is the intracranial course of the facial nerve?
Originates between the pons and medulla > Internal acoustic meatus >Facial canal (petrous part of the temporal bone) >exists through the stylomastoid foramen
Branches of the facial nerve
Divides into 5 branches within the parotid gland
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
Branches before entering the parotid gland
- Digastric
- Posterior auricular
- Cervicofacial
- Temporofacial
Which cranial nerves transmit parasympathetic fibres?
Oculomotor, glossopharyngeal, vagus and facial
What is the surface anatomy of the parotid duct?
The middle third of a line drawn between the intertragic notch and the middle of the philtrum
Where does the parotid duct open?
Crosses the masseter, pierces the buccinator and opens adjacent to the upper 2nd molar (stensen’s duct)
Which structures pass through the parotid gland?
Facial nerve (most superficial structure)
External carotid artery
Retormandibular vein
Auriculotemporal nerve
Deep parotid lymph nodes
What are the relations of the parotid gland?
Anterior - masseter, medial pterygoid, superficial temporal and maxillary arteries, facial nerve and stylomandibular ligament
Posterior - posterior belly of digastric muscles, SCM, Stylohyoid, internal carotid artery, mastoid process and styloid process
What is the arterial supply of the parotid gland?
Branches of the external carotid artery
What is the venous drainage of the parotid gland?
Retromandibular vein (union of the superficial temporal and maxillary veins)
What is the lymphatic drainage of the parotid gland?
Deep and superficial parotid LN > upper and lower deep cervical lymph nodes
What is the innervation of the parotid gland?
Parasympathetic - secretomotor from the otic ganglion
Sympathetic - superior cervical ganglion
Sensory - greater auricular nerve
What is the surface anatomy of the parotid gland
Upper end - curved line from the tragus to the centre of the mastoid bone
Anterior border - a line from the tragus to the centre of the posterior border of the masseter then to the point 2cm below and behind the angle of the mandible
Posterior - straight line from the mastoid process to a point 2cm below and behind the angle of the mandible
What type of secretions does the parotid gland produce?
Serous
parasympathetic stimulation produces watery serous saliva
Sympathetic stimulation produces low volume, enzyme rich saliva
Name some differential diagnoses of a parotid swelling
Infection - parotitis, mumps
Obstructed duct - calculi, external compression
Neoplasm- pleomorphic adenoma, warthin’s tumour
Deep parotid lymph node
What is Frey syndrome?
Damage to the parasympathetic fibres from the auriculotemporal nerve results in excessive gustatory sweating in response to saliva production