PAROTID GLAND

Dr. P. Ravisankar, Ph.D

Professor of Anatomy

SRMDC & Hospital

SRMIST- Ramapuram

Chennai-600089, Tamil Nadu, India.

THE SALIVARY GLANDS

INTRODUCTION

➢ Discharge the secretion into oral cavity.

➢ Major salivary glands-has extra glandular duct

eg. Parotid, Submandibular & Sublingual.

➢ Minor salivary glands – Lie in the sub-mucosa of

mouth open directly or indirectly

Eg- Anterior lingual, Von ebner, Small labial,

Buccal and palatal gland

FUNCTIONS OF SALIVARY GLANDS

➢ Lubrication of food-Assisting swallowing.

➢ Moistening of the buccal mucosa – essential for

speech.

➢ Provision of an aqueous solvent – necessary for

taste.

➢ Provision of fluid – necessary of suckling.

➢ Secretion of digestive enzymes and hormones

and other active components.

CONTENTS➢ PAROTID REGION & BED

➢ INTRODUCTION

➢ CAPSULE

➢ EXTERNAL FEATURES

➢ RELATIONS – STRUCTURES WITHIN THE GLAND

➢ STRUCTUER OF THE GLAND

➢ PAROTID DUCT

➢ BLOOD SUPPLY

➢ VENOUS DRAINAGE

➢ LYMPHATIC DRAINAGE

➢ NERVE SUPPLY

➢ DEVELOPMENT

➢ APPLIED ANATOMY

➢ REFERENCES

PAROTID REGION

Anteriorly – Anterior border of masseter

Superiorly – Zygomatic arch

Posteriorly –Mastoid process

Inferiorly – line bet. Angle of mandible and

mastoid process

PAROTID BED

PAROTID GLAND

INTRODUCTION

➢ Largest of the three major salivary glands.

➢ Occupies the retromandibular space- between

the ramus of the mandible in front and the

mastoid process and the sternocleido-mastoid

muscle behind.

➢ Type of serous salivary gland.

➢ Varies in weight from 14 to 28 gm.

➢ It lies upon the side of the face, immediately

below and in front of the external ear.

➢ The main portion of the gland is superficial,

somewhat flattened and quadrilateral in form.

➢ The remainder of the gland is irregularly wedge-

shaped, and extends deeply inward toward the

pharyngeal wall

CAPSULE

➢ The gland is enclosed within a capsule

continuous with the deep cervical fascia

➢ The layer covering the superficial surface is dense

and closely adherent to the gland

➢ Deep portion of the fascia, is thickened to form

the stylomandibular ligament which intervenes

between the parotid and submaxillary glands

THE PAROTID GLAND

EXTERNAL FEATURES

Three sided pyramid

Apex – directed downward

SURFACES

Base or superior surface

Superficial

Anteromedial

Posteromedial

BORDERS

Posterior, anterior & medial

PROCESSES

Facial process

Post glenoid process

Pterygoid process

RELATIONS

➢ Apex – overlaps the post. Belly of digastric and

carotid triangle

➢ Cervical branch of facial nerve and two divisions

of retro-mandibular vein emerges.

RELATIONS

SUPERFICIAL SURFACE

➢ Slightly lobulated,

➢ Covered by the superficial fascia containing the

facial branches of the great auricular nerve and

some small lymph glands.

➢ The fascia which forms the capsule of the gland.

➢ Post. Fibres of platysma

➢ Few lymph nodes

ANTERO-MEDIAL SURFACE

➢ The gland is moulded on the posterior border of

the ramus of the mandible,

➢ Medial pterygoid and Masseter.

➢ The inner lip of the groove dips,between the two

Pterygoid muscles, while the outer lip extends

for some distance over the superficial surface of

the Masseter; a small portion of this lip

immediately below the zygomatic arch is usually

detached, and is named the accessory part of the

gland.

POSTEROMEDIAL SURFACE

➢ Grooved longitudinally against the EAM, the

mastoid process,& the anterior border

Sternocleidomastoideus.

➢ Posterior belly of digastric

➢ Styloid process & its structures

➢ ECA enter and ICA lies deep to styloid process.

SUPERIOR SURFACE

➢ It is concave

➢ Cartilaginous part of external acoustic meatus

➢ Posterior surface of the temporomandibular

joint

➢ Superficial temporal vessels and

auriculotemporal nerve.

BORDERS

ANTERIOR BORDER

➢ Parotid duct

➢ Transverse facial vessels

➢ Most of the terminal branches of facial nerve

➢ Accessory parotid gland

POSTERIOR BORDER

➢ Overlop the sternocleiodmastoid

➢ Medial border – lateral wall of pharynx

STRUCTURES WITHIN THE GLAND

FROM DEEP TO SUPERFICIAL

➢ ECA lies at first on the deep surface, and then in

the substance of the gland.

➢ It gives its posterior auricular branch from the

gland behind- divides into its terminal branches,

maxillary and superficial temporal

➢ Maxillary artery runs forward deep to the neck of

the mandible

➢ Superficial temporal artery- upward across the

zygomatic arch and gives off its transverse facial

artery.

RETROMANDIBULAR VEIN

➢ Superficial temporal and Maxillary veins-

posterior facial vein - this vein splits into anterior

and posterior divisions.

➢ The AD unite with the anterior facial to form the

common facial vein

➢ The PD unites in the gland with the posterior

auricular to form the EJV.

PATEY’S FACIOVENOUS PLANE

FACIAL NERVE

➢ The facial nerve enters to the gland through

upper part of posteromedial surface and divides

into its terminal branches within the gland.

.

➢ Branches leave the gland through antero-medial

surface and then anterior border.

➢ Branches of the great auricular nerve pierce the

gland to join the facial.

STRCTURE OF PAROTID GLAND

➢ Has capsule

➢ Compound tubulo-alveolar gland

➢ The glandular tissue made up of mainly serous

acini less mucous acini

➢ Connective tissue containing adipose tissue,

blood vessels and inter lobular and intralobular

ducts are seen

THE PAROTID DUCT

➢ Also known as “STENSON’S DUCT”➢ About 5 cm in length

➢ Runs forwards, downwards and peirces the

following structures

Buccal pad of fat

Buccopharyngeal fascia

Buccinator

Oral mucosa – vestibule of mouth opposite

the crown of the upper second molar tooth.

STRUCTURE OF PAROTID DUCT

➢ It is dense, wall being of considerable thickness

➢ Its canal is about the size of crow-quill, but at its orifice on the oral surface of the cheek its lumen is greatly reduced in size.

➢ It consists of a thick external fibrous coat which contains contractile fibers and

➢ An internal or mucous coat lined with short columnar epithelium.

BLOOD SUPPLY

ECA- branches given off by that vessel in or

near its substance

VENOUS DRAINAGE

The veins empty themselves into the EJV,

through some of its tributaries.

LYMPHATIC DRAINAGE

The lymphatics -superficial and deep cervical

lymph nodes, passing in their course through

two or three nodes, placed on the surface and in

the substance of the parotid

Upper deep cervical lymph nodes

NERVE SUPPLY

The nerves are derived from the plexus of the

sympathetic on the ECA, the facial, the

auriculotemporal, and the great auricular

nerves.

Parasympathetic nerve – secretomotor

Inferior salivary nucleus 9th cranial nerve

(tympanic branch) Tympanic plexus

Lessor petrousal nereve Otic ganglion

Auriculotemporal nerve Parotid gland

NERVE SUPPLY

DEVELOPMENT

It arise as ectodermal diverticulum from the lining

epithelium of the mouth

First it appear as an elongate furrow between the

mandibular and maxillary processes

Then it converted into tube and loses its

connection with the epithelium of mouth

The ventral end grows dorsally into the substance

of the cheek.

APPLIED ANATOMY

1. External fistulae of parotid duct

Obstruction of duct due strictures or tumors

Due to injury OR sialolith (calculus)

Can be observed by x-ray- sialography

During the surgery the facial nerve,

retromandibular vein & external carotid artery

should be borne in mind.

2. FREY’S SYNDROME OR AURICULO-

TEMPORAL SYNDROME

After the surgery of parotid or Parotidectomy

the skin of temple appear as redness and

sweating due to injury to auriculo-temporal

nerve.

3.PAROTID ABSCESS

Due to spread of infection from mouth cavity

because of defective oral hygiene.

It may press on the facial nerve – cause paralysis.

4. PAROTID SWELLINGS

Very painful due to the unyielding nature of parotid fascia.

5. Mumps

Infectious disease of parotid gland caused by

specific virus

6. Mixed parotid tumors

In initial stage it is painless later it may be as malignant inducing pain and cause hardness of the gland leads enlargement of lymph nodes and involvement of facial nerve

REFERENCES

1. TEXT BOOK OF ANATOMY 3rd VOLUME

3RD ED. VISHRAM SINGH

2. GRAY’S ANATOMY 40TH ED. – SUSAN &

SANDRING

3. BD CHAURASIA’S HUMAN ANATOMY 3RD VOLUME ,8TH ED- KRISHNA GARG

4. CLINICALLY ORIENTED ANATOMY

3RD ED. KEITH L.MORE

THANK YOU