PAROTID GLAND

parotid region

features

largest of salivary

situated below external acoustic meatus

between the ramus of mandible and sternocleidomastoid

skin over supplied by greater auricular

structures within parotid

arteries

external carotid artery enters through posteromedial surface

maxillary artery leaves the 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

union of

superficial tempora and maxillary veins

in lower part of vein divides in t

these emerge close the apex (lower pole

anterior division

posterior division

facial is the 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

branches at its exit from stylomastoid foramen

communicating branches with adjacent cranial and spinal nerves

posterior auricular 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

short and supplies posterior belly of digastric

stylohyoid branch arises with digastric branch

long and supplies stylohyoid

terminal branches

temporal branches cross zygomatic arch and supply

auricularis anterior

auricularis superior

intrinsic muscles on the lateral side of

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

to platysma

crosses of mandible supplies

muscles of lower lip and chin

cervical branch

emerges from apex of parotid

runs downwards and forwards in the neck to supply platysma

bells palsy

sudden paralysis of facial at stylomastoid foramen

results in asymmetry of of

inability to close

dissapearance of nasolabial fold

loss of wrinkling of skin of forehead on same side

supply

parasympathetic nerves are secretomotor

reach the through auriculotemporal

preganglionic fibres begin in inferior salivatory nucleus

pass through glossopharyngeal

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 come from

auriculotemporal

parotid fascia innervated by sensory fibres of great auricular

parotid duct or stensons duct

superiorly

accessory parotid

transverse facial vessels

upper buccal branch of facial

inferiorly

lower buccal branch of facial

anterior border of masseter

parotid duct turns medially and pierces

buccal of fat

buccopharyngeal fascia

buccinator

contains

largest salivary

histology

it is a serous acini

external features

surfaces

superior (base of pyramid)

forms the upper end of the

small and concave

related to cartilaginous part of external acoustic meatus

posterior surface of temporomandibular joint

superficial temporal vessels

auriculotemporal

superficial

largest surface

covered by

skin

superficial fascia

containing anterior branches of great auricular

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

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

enter the through this surface

internal carotid artery lies 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

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 formed in the parotid duct