parotid region

• features
• largest of salivary gland
• situated below external acoustic meatus
• between the ramus of mandible and sternocleidomastoid
• skin over gland supplied by greater auricular nerve
• structures within parotid gland
• arteries
• external carotid artery enters gland through posteromedial surface
• maxillary artery leaves the gland through its anteromedial surface
• superficial temporal artery gives transverse facial artery and emerges at the
• anterior part of superior surface
• veins
• retromandibular vein is formed within the gland
• union of
• superficial tempora and maxillary veins
• in lower part of gland vein divides in t
• these emerge close the apex (lower pole
• anterior division
• posterior division
• nerve
• facial nerve is the nerve of second branchial arch
• leaves the skull by passing through stylomastoid foramen
• extracranial course
• 1. crosses the lateral side of base of styloid process
• then enters the posteromedial surface of partodi gland
• branches at its exit from stylomastoid foramen
• communicating branches with adjacent cranial and spinal nerves
• posterior auricular nerve arises just below the stylomastoid foramen
• ascends between mastoid process and external acoustic meatus
• supplies
• auricularis posterior
• occipitalis
• intrinisic muscles on back of auricle
• digastric branch arises close to previous nerve
• short and supplies posterior belly of digastric
• stylohyoid branch arises with digastric branch
• long and supplies stylohyoid muscle
• terminal branches
• temporal branches cross zygomatic arch and supply
• auricularis anterior
• auricularis superior
• intrinsic muscles on the lateral side of ear
• frontalis
• orbicularis oculi
• corrugator supercili
• zygomatic branches
• run across zygomatic bone
• supply orbicularis oculi
• buccal branches are two in number
• marginal mandibular branch
• runs below the angle of mandible
• deep to platysma
• crosses body of mandible supplies
• muscles of lower lip and chin
• cervical branch
• emerges from apex of parotid gland
• runs downwards and forwards in the neck to supply platysma
• bells palsy
• sudden paralysis of facial nerve at stylomastoid foramen
• results in asymmetry of corner of mouth
• inability to close eye
• dissapearance of nasolabial fold
• loss of wrinkling of skin of forehead on same side
• nerve supply
• parasympathetic nerves are secretomotor
• reach the gland through auriculotemporal nerve
• preganglionic fibres begin in inferior salivatory nucleus
• pass through glossopharyngeal nerve
• tympanic branch
• relay in otic ganglion
• sympathetic nerves
• postganglionic
• vasomotor
• derived from plexus around middle meningeal artery
• travel along branches of maxillary,external carotid artery and their branches
• sensory nerves
• to the gland come from
• auriculotemporal nerve
• parotid fascia innervated by sensory fibres of great auricular nerve
• parotid duct or stensons duct
• superiorly
• accessory parotid gland
• transverse facial vessels
• upper buccal branch of facial nerve
• inferiorly
• lower buccal branch of facial nerve
• anterior border of masseter
• parotid duct turns medially and pierces
• buccal pad of fat
• buccopharyngeal fascia
• buccinator
• contains
• largest salivary gland
• histology
• it is a serous acini
• external features
• surfaces
• superior (base of pyramid)
• forms the upper end of the gland
• small and concave
• related to cartilaginous part of external acoustic meatus
• posterior surface of temporomandibular joint
• superficial temporal vessels
• auriculotemporal nerve
• superficial
• largest surface
• covered by
• skin
• superficial fascia
• containing anterior branches of great auricular nerve
• preauricular or superficial parotid lymph nodes
• posterior fibres of platysma
• risorius
• parotid fascia which is thick and adherent
• anteromedial
• grooved by posterior border of ramus of mandible
• related to
• masseter
• lateral surface of temporomandibular joint
• posterior border of the ramus of mandible
• medial pterygoid
• emerging branches of facial nerve
• posteromedial
• moulded to mastoid
• moulded to styloid processs
• structures attached to them
• related to
• mastoid process
• sternocleidomastoid
• posterior belly of digastric
• styloid process with structures attached to it
• external carotid artery and facial nerve
• enter the gland through this surface
• internal carotid artery lies deep to styloid process
• relations
• borders
• anterior
• separates superficial surface from anteromedial surface
• extends from anterior part of the superior surface to the apex
• following structures emerge at this border
• parotid duct
• terminal braches of facial nerve
• transverse facial vessels
• posterior
• separates superficial surface from posteromedial surface
• overlaps sternocleidomastoid
• medial / pharyngeal edge
• - separates anteromedial surface from posteromedial surface
• sep
• related to lateral wall of pharynx
• blood supply
• parotid lymph nodes
• CLINICAL ANATOMY
• parotid abscess
• caused by spread of infection from opening of parotid duct
• drained by making holes (hiltons method)
• mixed parotid tumour is slow growing tumour
• parotid calculi may be formed in the parotid duct