Major salivary gland by Dr.Hardik Rupareliya
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Transcript of Major salivary gland by Dr.Hardik Rupareliya
Anatomy of
Salivary Glands
Embryology
Salivary glands develop as outgrowths of buccal epithelium.Parotid – ectodermal in origin
Submandibular& Sublingual – endodermal in origin
Parotid – 4th Wk of gestationSubmandibular – 6th Wk of gestationSublingual – 9th Wk of gestation
IntroductionSalivary Gland is any cell or organ discharging a secretion into the oral cavity.
Major and minor Salivary Glands
Major (Paired)
Parotid Submandibular
SublingualMinor
Those in the Tongue, Palatine Tonsil, Palate, Lips and Cheeks
•Main function of Salivary Gland-
secretion of saliva
•Daily secretion -800 to 1500 ml
•pH : 6-7
Saliva Compositon
Water (99.5%) Solid (0.5%)
Organic Inorganic
PtyalinMucin
LysozymeIgA
Lactoferrin
Na+K+
Ca+Cl-
HCO3Mg
Functions of Saliva
Keep the mouth moistAids in swallowingAids in speechKeeps the mouth and teeth cleanAntimicrobial actionDigestive functionBicarbonate acts as buffer
Parasympathetic stimulation - profuse secretion of watery
saliva
Sympathetic stimulation - scanty viscous secretion
Sympathetic supply comes from cervical sympathetic chain along the blood vessels
Salivatory nuclei are excited by
Taste and tactile stimuli from tongue and other areas of mouth and pharynx
Stimuli from esophagus and stomach (due to stimulation of vagal afferent fibers
(unconditioned reflex)
Stimuli arising from higher centers of brain due to sight, smell or thought of food
(conditioned reflex.)
Largest salivary paired gland )weighs15gms(
Secretions of which is serous in nature
2 lobes
1)Superficial
2)Deep
Site
Angle of Mandible
Sternomastoid
Auricle
Head ofMandible
Middle ofMasseter m.
2 cm belowAngle ofMandible
MastoidProcess
Surface Anatomy of Parotid Duct
Tragus ofthe ear
Midway between the ala of the nose
and the angle of the mouth
Middle ⅓ of the horizontal line
RELATIONSRELATIONS
1. Superficial Temporal vessels.Auriculotemporal nerve.
2. Cartilaginous part of External Auditory Meatus.
3. Temporal branch of Facial n.
Upper Part
1. Cervical branch of Facial n.
2. Retromandibular vein.
3. Posterior belly of digastric.
4. External Carotid artery.
Lower Part
• Zygomatic branch of Facial n.
• Transverse Facial artery.
• Buccal branch of Facial n.
• Accessory Parotid gland.
• Parotid duct.
• Mandibular branch of Facial n.
Anterior Border
1. Great Auricular nerve.
2. Parotid lymph nodes.
3. Skin and Fascia
Lateral Surface
1. Ramus of the mandible.
2. Masseter muscle.
3. Medial pterygoid muscle
Antero-Medial Surface
1. Mastoid process
2. Sternomastoid muscle
3. Posterior belly of Digastric
4. Styloid process and the muscle & ligaments attached to it.
5. Internal carotid artery & Internal jugular vein (carotid sheath).
Postero-Medial Surface
1. External carotid artery
2. Retromandibular vein
3. Facial nerve –enters the gland posteromedially,and divides into terminal branches within gland,and leaves the gland through anteromedial surface.
Structures within the Gland
Capsule
1.False Capsule1.False Capsule
Capsule
1.False Capsule
2.True Capsule
1.False Capsule
2.True Capsule
Accesory PartSemidetached part of the gland, which lies just above the parotid
duct
Semidetached part of the gland, which lies just above the parotid
duct
Parotid Duct5 cm long & emerges from
the anterior border & runs superficial to masseter m.
5 cm long & emerges from
the anterior border & runs superficial to masseter m.
•At the anterior border of masseter it pierces
•Buccal pad of fat•Buccopharyngeal fascia•Buccinator Muscle
•It opens into the vestibule of mouth opposite to the 2nd
upper molar
ARTERIAL SUPPLY
External Carotid Artery
Venous Drainage
Retromandibular Vein drain into the internal jugular vein
LYMPHATIC DRAINAGE
Lymph first drains into parotid nodes and then upper deep cervical nodes
Nerve Supply
1. Sensory:
a. Gland:
Auriculotemporal nerve
a. Capsule:
Great Auricular nerve
Nerve Supply
2. Sympathetic:
From the sympathetic plexus around the external carotid.
3. Parasympathetic:
The preganglionic secretomotor fibers arise from the inferior salivary nucleus in the medulla oblongata.
Joins the glossopharyngeal nerve (9th cranial) , tympanic branch ,tympanic plexus,Lesser Petrosal nerve
Enters the foramen ovale to relay in the otic ganglion
The post ganglionic fibres pass through auriculotemporal nerve through which they reach the gland
MedullaOblangata
InferiorSalivaryNucleus
Glossopharyngeal n.
TympanicPlexus
LesserPetrosal n.
OticGanglion
Auriculotemporal n.
Frey syndrome
Also called as auriculotemporal nerve syndrome or gustatory sweating
It is condition wherein sweating in the area of distribution of ATN occurs,which is caused by a stimulus to secretion of saliva.
It is thought to be the result damage to ATN post ganglionic parasympathetic fibres from otic ganglion become united to sympathetic fibres arising from superior cervical ganglion going to supply sweat gland
Surgical approches
Pre auricular
Submandibular
Combination of both
SubmandibularGland
SubmandibularGland
SiteAnterior part of Digastric triangle,
It is roughly j-shaped
Mixed secretion but predominantly serous
Parts1. Superficial part
2. Deep part
3. Submandibular duct
Superficial partDeep part
Submandibular duct
Superficial Part Wedge shaped, extending:Posteriorly: to the angle of mandible.Superiorly: to mylohyoid line of mandible.Inferiorly: it overlaps the 2 bellies of digastric m
Relations1. Inferolateral surface: related to skin, superficial fascia )containing
platysma, cervical branch of facial n., . facial vein, Lymph Nodes( & deep fascia.
2. Lateral surface: related to body of mandible, facial artery, mylohyoid nerve & artery
3. Medial surface: related to 2 muscles )mylohyoid & hyoglossus( & 2 nerves )lingual & hypoglossal(.
Deep PartSmall part lying deep to mylohyoidSuperficial to hyoglossusBetween lingual nerve above & hypoglossal nerve
below
Mylohyoid
Lingual n.
Submandibluar duct
Whartons duct5 cm long
Emerges at the anterior end of deep part of the glandRuns forwards on hyoglossus b/w lingual and hypoglossal NAt the ant. Border of hyoglossus it is crossed by lingual nerveOpens in the floor of mouth at the side of frenulum of tongue
Blood Supply
ArteriesBranches of facial and lingual arteries
VeinsDrains to the common facial or lingual veins
LymphaticsDeep Cervical Nodes via submandibular nodes
Nerve Supply
1.Sensory: Lingual nerve
2.Sympathetic: Plexus around the facial artery
3.Parasympathetic:Chorda tympani from Facial nerve
Sublingual Salivary Glands
smallest of the three glands
weighs nearly 3-4 gm
Lies beneath the oral mucosa in contact with the sublingual fossa on lingual aspect of mandible. Mixed secretion but predominantly mucous
RelationsAbove the mylohyoid below the mucosa of floor of mouthMedial to sublingual fossaLateral to genioglossus
DuctDucts of Rivinus
8-20 ductsLargest of all,sub lingual duct(bartholin duct) joins sub mandibular duct to drain through sublingual caruncle,Most of them open directly into the floor of mouth
Blood supplyArterial from sublingual and submental arteriesVenous drainage corresponds to the arteries
Nerve SupplySimilar to that of submandibular glands( via lingual nerve , chorda tympani and sympathetic fibers)
DISORDERS OF SALIVARY GLAND
CLASSIFICATION OF SALIVARY GLAND DISORDERS
A) Developmental disorders
Aberrancy
Aplasia & Hypoplasia
Hyperplasia
Atresia
Accessory ducts
Diverticuli
Congenital fistula
B( Functional disordersSialorrhoeaXerostomia
C( Obstructive disordersSialolithiasisMucus plugStricture & stenosisForeign bodiesExtra ductal causes
D( Cyst
Mucocele
Ranula
E( Asymptomatic enlargement
Sialosis
Allergic
Associated with malnutrition and alcoholism
F( Infection
Viral
Bacterial
Mycotic
G( Autoimmune disorders
Sjogren’s syndrome
Mikulicz’s disease
Uveoparotid fever
Recurrent non specific parotitis
Blue pigmented swelling
Plunging Ranula Ranula
Non-invasive investigationsRadiographsComputerized TomographyUltrasound scanningMagnetic resonance imagingSingle Photon emission Computed Tomography
Invasive InvestigationsBiopsyFine needle Aspiration cytology
Sialography
ThankYou