Parotid gland Flashcards
boundaries of the parotid bed/retromandibular fossa
Anterior: Mandible ramus posterior border , Masseter (laterally), Medial pterygoid (medially)
Posterior: mastoid process covered by sternocleidomastoid laterally
Superior: external acoustic meatus and posterior part of TMJ
Inferior: line joining angle of mandible to mastoid process
Medially: styloid process with stylohyoid, styloglossus, & stylopharyngeus
Extent of parotid gland
Superior; up to external acoustic meatus
Inferior; line joining angle of mandible to mastoid
Anterior; overlaps masseter posterior border
Posterior; overlaps sternocleidomastoid anterior border
Medially; close to pharynx wall (styloid process)
Location of accessory parotid gland and from which structure does it emerge?
Located between zygomatic arch superiorly and parotid duct inferiorly
Emerges from anterior aspect of parotid gland
Which layer of deep cervical fascia forms the false capsule?
Investing layer
The false capsule is also the
parotid fascia
Structure formed by deep lamina of parotid fascia and its significance
stylomandibular ligament
separates parotid gland from submandibular gland
Relations of the apex of parotid gland
- retromandibular vein and its divisions
- cervical branch of facial nerve
- posterior digastric
- upper carotid triangle
relations of lateral/superficial surface of parotid gland
skin
superficial fascia containing (preauricular/superficial parotid lymph nodes, greater auricular nerve, and platysmaO
parotid fascia superficial lamina
deep parotid lymph nodes
Attachments of superficial and deep laminae of parotid fascia
superficial lamina attaches to inferior border of zygomatic arch
deep lamina attaches to styloid process and tympanic plate
State relations of the anteromedial surface
Masseter
Mandible ramus
Medial pterygoid
TMJ lateral aspect
State the relations of the posteromedial surface
mastoid sternocleidomastoid styloid digastric posterior belly facial nerve external carotid artery
The parotid gland is separated from which structures by the styloid process and its attachmed muscles
Internal jugular vein
Internal carotid artery
Last 4 cranial nerves
Superficial lamina of parotid fascia also called
parotidomasseteric fascia
State the structures within the partoid gland from superficial to deep
*MNEMONIC: Not Vlogging Again :(
facial Nerve
retromandibular Vein
external carotid Artery
Formation of retromandibular vein
union of maxillary and superficial temporal veins
Which part of the parotid gland is affected in Pleomorphic adenoma?
the large superficial part
Pleomorphic adenoma is another name for
Mixed parotid tumor
clinical significance of patey’s faciovenous plane
the plane between the superficial and deep lobes of parotid gland where the vessels and nerves lie. surgeons cut parallel to the nerve in this plane to avoid damaging it as they remove parotid tumors
Parotid duct is also called
Stenson’s duct
At which point does Stenson’s duct emerge into the mouth?
opposite crown of upper second molar tooth
Course of stenson’s duct
travels forward just anterior to masseter anterior border
bends medially to pierce buccal pad of fat, buccopharyngeal fascia, and buccinator
runs forward between buccinator and buccal mucous membrane
bends medially to pierce buccal mucous membrane to emerge at mouth vestibule opposite crown of upper 2nd molar tooth
Importance of tortous course of parotid duct
acts like a valve to prevent the duct from swelling during excessive blowing/whistling
surface anatomy of parotid duct
line from tragus to midpoint of line between ala of nose and upper lip
Jacobson’s nerve
is the tympanic branch of glossopharyngeal nerve that carries the preganglionic parasympathetic nerve fibers
Explain the parasympathetic pathway for parotid gland innervation
Inferior salivatory nucleus –> glossopharyneal nerve –> temporal branch of glossopharyngeal nerve –> lesser petrosal nerve –> otic ganglion
Enumerate innervation of parotid gland
Parasympathetic innervation via auriculotemporal nerve - produces water saliva
Sympathetic innervation via superior cervical sympathetic ganglia - produces thick, sticky saliva
Sensory innervation is by auriculotemporal and great auricular nerve (c2 & 3)
Frey’s syndrome
damage to auriculotemporal and great auricular nerve causes them to grow back in the same sheath. therefore, signals for salivation signal the sensory nerves for heat, pain, touch.
Person sweats over parotid region during eating.
Posterior auricular nerve is given off at
root of styloid process
Mumps
swelling of parotid due to inflammation by infection of myxovirus (mumpus virus)
complications in adults include swelling of testes(epididimo-orchitis), inflammation of ovaries(oophoritis), and pancreas (pancreatitis) inflammation
Lymphatic drainage of parotid gland
drained by superficial (pre-auricular) and deep parotid lymph nodes which go to drain into deep cervical lymph nodes
Parotid gland derived from which embryologic germ layer
ectoderm
Embryologic development of parotid gland
Week 6, cord of ectodermal cells at vestibule of primitive mouth grow backwards to form parotid duct
Describe Hilton’s method
a method in which cut in the parotid fascia is made horizontal to the facial nerve to avoid injuring it during drainage of abcess
