anatomy of the parotid gland
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Anatomy of the ParotidAnatomy of the Parotid
GlandGland
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Parotid Gland
Is the largest of the major salivary
glands, It is a mainly serous gland It is a
large, irregular, lobulated gland which
extends from the zygomatic arch to theupper part of the neck, where it overlaps
the posterior belly of digastric and the
anterior border of sternocleidomastoid.
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Anteriorly the gland overlaps masseter and a small, usuallydetached accessory parotid lies above the parotid duct on theaponeurotic part of masseter.
he gland extends below the external acoustic meatusposteriorly onto the mastoid process. In transverse section the gland is wedge!shaped, occupying the gap between theramus of the mandible and the mastoid and styloid
processes of the temporal bone, and reaching close to thelateral wall of the oropharynx.
"n accessory parotid gland usually lies on the masseter
between the duct and the zygomatic arch. #everal smallducts open from it into the parotid duct. It and the duct
lie on the aponeurotic part of the surface of the masseter
muscle.
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he Parotid Gland has three surfaces$%ateral uperficial', Posteromedial ( "nteromedialsurfaces.
Posteriorfacial vein
)xternal ca
rotid
artery
Portion behind
styloid process
#uperficial temporal
artery
*axillary artery
Portion anterior to
styloid
Impression for
the mandible
Impression for
#tyloid process
Parotid
tensen' +uct
Parotid tensen' +uct
Impression for *astoid process
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he lateral &superficial' surface of the gland is
covered by skin and superficial fascia. heinvesting layer of deep cervical fascia splits to
envelope the gland and form the Parotid
capsule.he acial nerve branches penetrate the fascia
as they proceed peripherally to inervate
overlying facial muscles.
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he great auricular nerve supplies the fascia
superficial and deep to the parotid gland, and
transmits the pain caused by stretching of thefascial envelope when acute enlargement of the
gland occurs as in mumps.
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%eft Parotid )xposure
"nt.Post.
-ut ends of Great auricular nerve
sacrificed during parotid surgery
Parotid gland
#ternomastoid
muscle
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he anteromedial surface is grooved by the posterior
border of the mandibular ramus, and is related to the
masseter and medial pterygoid muscles which are
attached to the ramus.
he anterior edge of this surface meets the lateral
surface over, as well as below, the masseter forming the
irregularly convex anterior border of the gland.
he parotid duct and the facial nerve branches
emerge from the anteromedial surface and run forwards
deep to the anterior border. he terminal branches ofthe external carotid artery &superficial temporal and
maxillary' leave this surface further back.
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"nteromedial #urface of Parotid gland
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he posteromedial surface is in contact with themastoid process with its attachedsternocleidomastoid and posterior belly of
digastric muscles.*ore medially, the styloid process and itsattached muscles &stylohoid, stylopharyngeus
and styloglossus' separate the gland from thecarotid sheath and its contained internal jugularvein and internal carotid artery.
he external carotid artery enters the gland
through the lower part of this surface.he facial nerve trunk, or its temporofacial andcervicofacial divisions, enter the gland between
the mastoid and styloid processes.
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Posteromedial surface of parotid gland
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*edial relations of the Parotid gland &parotid bed'
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#tructures passing through the gland
acial nerve ( its terminal branches
/etromandibular vein
)xternal -arotid artery ( its two terminal branches
0ranches of the Great auricular nerve
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1ithin the gland the branches of the facial nerve run in different directions corresponding with theirdestinations, i.e. scalp, eyelids, mid!face, lower
face and neck, and they do so in different(superficial to deep) planes. There is nospecific, developmentally determined plane inwhich the facial nerve branches pass betweensuperficial and deep lobes of the gland$ theparotid is an integral gland, not divided intolobes. 1ithin the gland the nerve branches
communicate with each other, forming aplexiform arrangement that lies superficial tothe retromandibular vein, which in turn issuperficial to the external carotid artery.
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he retromandibular vein is formed within the
parotid by the confluence of the superficial
temporal and maxillary veins.
he retromandibular vein emerges from the
lower part &pole' of the gland and divides into an
anterior branch which joins the facial vein and a
posterior branch which joins the posterior
auricular vein to form the external jugular vein$
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The parotid d ct (of tensen) abo t 2 cm long passes for ards across the
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The parotid duct (of tensen), about 2 cm long, passes forwards across the
masseter and turns around its anterior border to pass through the buccal fat
pad and pierce the buccinator .
he duct opens on the mucous membrane of the cheek opposite the second
upper molar tooth.
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he site of the orifice of the right parotid
duct is indicated by the bloody
discharge emanating from it in a patient
with a malignant parotid tumour. In the
absence of a discharge, the tiny orificeis barely visible.
!l d l
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!lood supply
0ranches from the external carotid artery supply
the gland. 3enous return is to the retromandibular
vein.
"ymph drainage
%ymph drains to the preauricular &parotid' nodesand thence to nodes of the upper group of deep
cervical nodes.
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#erve supply
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#erve supply
ecretomotor fibres arise from cell bodies in the otic ganglion
and reach the gland through the auriculotemporal nerve.
"s it passes backwards along the mandibular neck and ascendsbehind the temporomandibular$oint, the auriculotemporal nerveis in contact with the anteromedial surface of the gland, whichispenetrated by filaments from the nerve. he preganglionic
fibres arise from cell bodies in the inferior salivary nucleus in
the medulla, and travel by way of the glossopharyngeal nerve,its tympanic branch, the tympanic plexus and the lesser petrosalnerve to the otic ganglion.
ympathetic (vasoconstrictor) fibres reach the gland from
the superior cervical ganglion by way of the plexus on the
external carotid and middle meningeal arteries.
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