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ANATOMY OF PAROTID GLAND NOTES FOR FIRST YEAR MBBS

PAROTID GLAND
DESCRIBE PAROTID GLAND UNDER THE FOLLOWING HEADINGS (A)SURFACES, (B)BORDERS, (C)RELATIONS AND DUCT(D)CONTENTS (E)BLOOD AND NERVE SUPPLY (F)APPLIED ANATOMY(LE)
It is the largest of the salivary glands
Situated below the external acoustic meatus between the ramus of mandible and the sternocleidomastoid
Capsule:
Investing layer of deep cervical fascia
Superficial lamina- thick and adherent to gland
Deep lamina-thin
Stylomandibular ligament
(A)EXTERNAL FEATURES:
Gland resembles 3 sided pyramids
Apex directed downwards
4surfaces- Superior (base) Superficial
Anteromedial
Posteromedial
(B)BORDERS Anterior Posterior Medial
(C)RELATIONS Apex
Overlaps Posterior belly of digastric
Cervical branch of facial nerve
Retromandibular vein.
Superior surface
Cartilagenous part of external auditory canal
Temporomandibular joint
Superficial temporal vessels
Auriculotemporal nerve.
Superficial surface Largest of the 4 surfaces Skin
Superficial fascia –greater auricular nerve, preauricular lymph nodes, platysma Parotid fascia
Anteromedial surface
Grooved by the ramus of mandible
Masseter
Temporomandibular joint
Ramus of mandible
Medial pterygoid
Facial nerve- its emerging branches
Posteromedial surface
Moulded to the mastoid and styloid process
Mastoid process with sternocleidomastoid and posterior belly of digastric Styloid process with structures attached to it
External carotid artery enters this surface
Anterior border: Structures emerging from this border
Parotid duct
Terminal branches of facial nerve
Transverse facial vessels
Acccessory parotid gland.
Posterior border
Overlaps sternocleidomastoid
Medial border
Lateral wall of pharynx
(D)CONTENTS:
From Medial to lateral
Arteries
Veins
Facial nerve
Arteries
External carotid artery
Maxillary artery
Superficial temporal artery – transverse facial artey
Posterior auricular artery
Veins
Retromandibular vein is formed by union of superficial temporal and maxillary veins Vein divides into anterior and posterior divisions and emerge at the apex of gland.
Facial nerve enters through posteromedial surface and divides into 2 branches, Temporofacial – temporal and zygomatic
Cervicofacial – buccal , marginal mandibular, cervical
Facial nerve seperates large superficial part from small deep part.
PAROTID DUCT Thick walled 5 cm long
Emerges from the middle of anterior border of gland Runs downwards on masseter, Turns medially and pierces Buccal pad of fat
Buccopharyngeal fascia Buccinator
Opens into the vestibule of mouth opposite upper 2nd molar tooth.
(E)BLOOD SUPPLY
External carotid artery and its branches that arise within the gland. Veins drain into external jugular and internal jugular veins.
(E)NERVE SUPPLY
Parasympathetic nerves are secretomotor, Reach the gland through auriculotemporal nerve.
Sympathetic nerves are vasomotor.
Sensory nerves come from auriculotemporal nerve and greater auricular nerve.
(F)APPLIED ANATOMY
Mumps
Parotid abscess
Parotidectomy
Parotid calculi
Freys syndrome.
PAROTID DUCT(SE)
Thick walled
5 cm long
Origin - Emerges from anterior border of gland Related
Superiorly
To acessory parotid gland
Upper buccal branch of facial nerve
Transverse facial vessels.
Inferiorly
Lower buccal branch of facial nerve.
Runs on masseter and turns medially and pierces
Buccal pad of fat
Buccopharyngeal fascia
Buccinator(obliquely)
Oblique course of the duct through buccinator prevents inflation of the duct during blowing
The duct opens into the vestibule of the mouth opposite the crown of upper 2nd molar tooth.
PAROTID GLAND NERVE SUPPLY(SA)
Parasympathetic nerves are secretomotor, Reach the gland through auriculotemporal nerve
Sympathetic nerves are vasomotor
Sensory nerves come from auriculotemporal nerve and greater auricular nerve.
Inferior salivary nucleus (preganglionic fibres) -> Glossspharyngeal nerve
->Tympanic branch->lesser petrosal nerve-> Relay in otic ganglion-> Postganglionic fibres -> auriculotemporal nerve> Parotid gland.
STRUCTURES PRESENT WITHIN THE SUBSTANCE OF PAROTID GLAND(SA)
External carotid artery
Retromandibular vein
Facial nerve
TRACE THE PATHWAY FOR SECRETOMOTOR (PARASYMPATHETIC) FIBRES TO PAROTID GLAND (SA)
Inferior salivary nucleus (preganglionic fibres)
Glossspharyngeal nerve
Tympanic branch
Lessor petrosal nerve
This HTML is created from PDF
Relay in otic ganglion
Postganglionic fibres relay in auriculotemporal nerve
Parotid gland.

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