Download PAROTID REGION.

PAROTID REGION.
LEARNING OBJECTIVES.
 BY THE END OF THE LECTURE THE STUDENTS SHOULD BE ABLE TO KNOW:
 THE STRUCTURES FOUND IN THE PAROTID REGION.
 THE LOCATION OF PAROTID GLAND AND THE STRUCTURES RELATED TO
THE PAROTID GLAND.
 THE BLOOD SUPPLY AND THE INNERVATION TO THE PAROTID GLAND.
 THE CLINICAL ASPECT RELATED TO THE TOPIC.
PAROTID REGION.
The parotid region comprises of:
 Parotid salivary gland.
 The structures related immediately to it.
Parotid gland and related
structures.
o LARGEST of the salivary glands
o Purely SEROUS
o Inf. And anterior to Ext. Auditory Meatus
 Anteriorly
 Ramus of mandible
 Posteriorly
 SCM
o Wedge shaped (base-up ; apex-down)
o Duct: Stensen’s Duct
o Divided into 2 lobes by the FACIAL nerve
 Superior
 deep
o 3 processes:
 Glenoid:
 sup.; around temporo-mandibular joint
 Facial.
 Pterygoid:
 Between med-ptrygoid and ramus of the mandible
o Accessory parotid gland
 Small part of facial process separate from main gland
o Capsule
 Derived from investing layer of deep cervical fascia.
Parotid gland: Surface anatomy.
Structures within the parotid gland.
Lateral to medial
(N-V-A)
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Facial nerve.
RM vein.
External Carotid artery.
Parotid lymph nodes.
Scattered
Deep cervical LN (lymph
drainage).
Facial nerve.
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Emerges from:
 Stylomastoid foramen and enters the gland.
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Passes forward superficial to:
 RM vein.
 and Ext. Carotid Artery.
•Divides into 5 terminal branches on anteromedial surface of face
•Branches before entering the gland:
 Muscular nerve.
 Post belly of digastric .
 Stylohyoid.
 Post. Auricular nerve
 Post. And sup. Auricular muscles
 Occipital belly of Occipito-Frontalis.
RM vein.
•Venous drainage.
•Formed Within the gland
•Sup. Temportal and maxillary vein
•Divides into 2:
 Anteriorly+ facial vein = IJV
 Posteriorly+ post. Auricular = EJV (above SCM).
External carotid Artery.
o From common carotid artery
o Divides at the neck of the mandible
 Sup. Temporal artery
 Maxillary artery
Deep fascia does exist in the regions of the parotid glands and the
masseter muscles. It forms capsules around these structures.
Deep fascia does exist in the regions of the
parotid glands and the masseter muscles. It
forms capsules around these structures.
Parotid Gland: Relationships
Structures coursing within the parotid gland.
 Facial nerve
 Retromandibular vein
 External carotid artery
 Auriculotemporal nerve (from V3)
Parotid Gland: Relationship to the facial nerve.
Facial nerve: Deep and superficial course
Auriculotemporal nerve (from V3).
Supplies scalp & external ear
Carries postganglionic PS fibers that are secretomotor to the parotid.
Parotid (Stensen’s) Duct.
Penetrates buccal fat pad and buccinator  open into the oral cavity opposite
the 2nd maxillary molar tooth
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Arises from anterior border
1.5 cm inferior to Zygomatic arch
Pierces Buccinator at 2nd Molar
4-6 cm in length
5 mm in diameter
Parotid duct
 The only duct that opens to the oral vestibule
 Out of the gland at the anterior aspect, 1 finger beneath from
the zygomatic arch
 Masseter
 Inward: piercing buccal fat pad and buccinator

Papilla on 2nd lower molar tooth.
Parotid Capsule.
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Superficial layer Deep Cervical Fascia
Superficial layer
Deep layer
PAROTID GLAND
BLOOD SUPPLY AND LYMPHATIC DRAINAGE
 Branches of the external carotid artery traverse the glandular tissue and
supply the parotid.
 The main branch to supply the gland is the transverse facial artery.
 numerous local veins drain the organ.
 These veins drain into tributaries of external and internal jugular veins.
 The maxillary vein and superficial temporal vein meet to form the
retromandibular vein within the parotid gland, but are not responsible for
draining it.
 Lymphatics mainly comprise pre-auricular lymph nodes.
Innervation.
 Although the facial nerve (CN VII) runs through this gland, it does not
supply its parasympathetic innervation.
 Secretion of saliva by the parotid gland is controlled by presynaptic
parasympathetic .
 these leave the brain via the tympanic nerve branch of glossopharyngeal
nerve (CN IX) and reach the otic ganglion.
 After synapsing in the Otic ganglion, the postganglionic (postsynaptic) fibers
travel as part of the auriculotemporal nerve (a branch of the mandibular
nerve (V3)) to reach the parotid gland.
 Sympathetic nerves originating from Superior Cervical Ganglion and giving
rise to the external carotid nerve plexus reach the gland.
 Parasympathetic stimulation produces a water rich, serous saliva.
 Sympathetic stimulation leads to the production of a low volume, enzymerich saliva.
 This is done by vasoconstricting the blood supply to the parotid gland
reducing the potential for water collection. There is no inhibitory nerve
supply to the gland.
Bell’s Palsy.
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Paralysis of muscles of facial expression due to
damage/ inflammation of facial nerve.
Parotitis.
•Inflammation of one or both parotid glands is
known as parotitis.
•The most common cause of parotitis is mumps.
•Widespread vaccination against mumps has markedly
reduced the incidence of mumps parotitis.
•Other infections such as bacterial infections can cause
parotitis as may blockage of the duct, whether from salivary duct calculi or
external compression.
•Stones mainly occur within the main confluence of the ducts and within
the main parotid duct.
•The patient usually complains of intense pain when salivating and tends to
avoid foods which produce this symptom .
Salivary Gland Tumors.
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