Salivary glands finals OHE
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Transcript of Salivary glands finals OHE
THE SALIVARY GLANDS
WHAT IS THIS?
Saliva
complex fluid found lubricating the mucosa and teeth of the oral cavity
secreted by the salivary glands Major Minor
Types of Saliva
salivary glands, their cells and ducts are greatly responsible for the modification and kind of saliva being secreted
It is of three types: Serous Saliva Viscous Saliva Mixed Saliva
Serous Saliva
Content: Amylase protein polysaccharides
Cell: Serous Cells “watery saliva” Glands that secrete this type:
Parotid Gland Von Ebner’s glands
Viscous Saliva
Content: Mucins (glycoproteins) Carbohydrates
Cell: Mucous Cells Thick and viscous Glands that secrete this type:
Sublingual Gland Minor Salivary Glands (except Von Ebner’s
glands)
Mixed Saliva
simply the combination of the aforementioned types of saliva
Able to do a multitude of significant functions
Secreted by: Submandibular Gland Sublingual Gland
Cells: Serous Cells Mucous Cells
Functions of Saliva
Main function: maintaining the well-being of the mouth
Other important functions: Protection Buffering Action Digestion Facilitation of Taste Defensive Action against Microbes Ionic Exchange between Tooth Surface
Functions of SalivaEffect Active
Constituent
Protection Lubrication, lavage, pellicle formation
GlycoproteinWater
Buffering Action Regulates pH Phosphate and Bicarbonate
Digestion Digests starchDigests lipidsBolus formation
AmylaseLingual Lipase
Facilitation of Taste Taste bud growth and maturation, dissolves substances to carry to taste buds
Gustin
Defensive Action Against Microbes
AntibodiesHostile Environment
LysozymeLactoferrinIgA
Ionic Exchange Between Tooth Surface
Posteruptive Maturation of EnamelRepair
CalciumPhosphate
MAJOR SALIVARY GLANDS
Major Salivary Glands
Functional Unit Parenchyma Stroma
In some books: salivon Three pairs:
Parotid glands Submandibular glands Sublingual glands
Parotid Glands
In front of the ear behind the ramus of mandible
Purely serous Ptyalin and IgA Stensen’s duct-
opens opposite the upper second molar
Parotid Glands
Nerve supply: CN V Sympathetic control:
superior cervical ganglion
Parasympathetic control: CN IX, oticganglion
Submandibular Glands
Inner aspect of the mandible below the floor of the oral cavity
Mixed, 90% serous 10% mucous Secretes lysozymes Wharton’s duct: opens at each side of
the sublingual folds
Submandibular Glands
Serous demilunes
1: intralobular ducts/ striated ducts2: mucous acinus3: serous demilunes
Submandibular Glands
Nerve supply: CN V Sympathetic
control: superior cervical ganglion
Parasympathetic control: CN VII, chorda tympani, submandibular ganglion
Sublingual Glands
Floor of the mouth, below the tongue
Mixed, more mucous Ducts of Rivinus Bartholin’s duct:
opens into Wharton’sduct
Sublingual Glands
Nerve supply: CN V Sympathetic control: superior cervical
ganglion Parasympathetic control: CN VII, chorda
tympani, submandibular ganglion
MINOR SALIVARY GLANDS
MINOR SALIVARY GLANDS
Over 600 present in the oral cavity Types
Mucous producing minor salivary glands Serous fluid producing minor salivary
glands
Mucous Producing Minor Salivary Glands Submucosa of the oral mucosa 1-2 mm in diameter Not encapsulated Number of acini connected in a tiny
lobule
Serous Fluid Producing Minor Salivary Glands Aka. Von Ebner’s Glands Lipid hydrolysis and perception of taste Located around the foliate and
circumvallate papillae
Labial Glands
Inner surface of lips Mixed saliva Cells have distinct
mucoalbuminouscharacter
Terminal portions often form typicaldemilunes
Minor Buccal Glands
Continuation of the labial glands in the cheek
Lie within the vicinity of the opening of the parotid duct
Drain into the third molar region Therefore, it is known as molar glands
Glossopalatine Glands
Pure mucous glands Continuation of the lesser sublingual
glands (posteriorly) Ascend in the mucosa of the
glossopalatine fold
Palatine Glands
Pure mucous glands Occupy the roof of the oral cavity Divided into the glands of the:
Hard palate Soft palate and uvula
Glands of the Tongue
Anterior lingual gland Anterior part- chiefly mucous Posterior part- branching tubules lined with
mucous cells and capped with demilunes of serous cells
Posterior lingual glands Base of the tongue- purely mucous Glands of the vallate papillae (Von Ebner’s
glands)- purely serous, opens into the trough (depression) of the vallate papillae
Glands of the Tongue
Von Ebner’s Glands
STRUCTURES OF SALIVARY GLANDS
STRUCTURES OF SALIVARY GLANDS Parenchyma of glands consists of:
Secretory Portions Branching Duct Sytem
Lobules Septae Capsule
SECRETORY PORTIONS
Serous Cells
Seromucous cells Resemble
truncated pyramids
Tight junctions Junctional
complexes Collectively,
serous acini
Apical Cytoplasm of Serous Cells containing secretory granules
Mucous Cells
Adapted for production, storage, and secretion of proteinaceous material
Mucins Collectively,
mucous acini
Mucous Cells in tubulard secretory end pieces.
Mucous cells showing the serous demilunes.
Myoepithelial Cells
Flattened stellate cells
Desmosomes
Myoepithelial Cells
DUCTAL SYSTEM
Intercalated Ducts
Classified as intralobular duct
Smallest branch of the system of ducts
Prominent in Salivary Glands
Frequent in Parotid Gland
Striated Ducts
Formed by union of Intercalated Ducts
Terminal Excretory Ducts
Special eosinophilic cells
Terminal Excretory Ducts
Interlobular excretory duct
ADDITIONAL INFORMATION
SOURCE: MASTER DENTISTRY VOL. III: ORAL BIOLOGY
SALIVATION REFLEX ACTIVITY
Reflex Activity
Resting flow: keeps the mouth and oropharynx moist
Food and the prospect of eating: most saliva-inducing stimuli
Whole-mouth saliva contribution when stimulated: Parotid gland: 50% Submandibular gland: 30% Sublingual and minor salivary glands: 20%
Reflexes
Gustatory-salivary reflex Sour>umami>salty>sweet>bitter
Masticatory-salivary reflex Saliva flow is directly proportional to
masticatory forces Olfactory-salivary reflex
No reflex response from the parotid gland Increase in salivary secretion from the
submandibular and sublingual glands
Reflexes
Visual and psychic salivary reflex Stimuli: thought and sight of food
Oral nociceptor-salivary reflex Stimulation of the trigeminal afferent
nociceptive fibers Increase in parotid saliva secretion
Esophageal-salivary reflex Waterbrash phenomenon: sudden filling of
the mouth with fluids
DEVELOPMENT OF SALIVARY GLANDS
Development of Salivary Glands Derived from the oral mucosa Arise in weeks 5-6 of embryonic life
Development of Salivary GlandsPRIMORDIA TIME OF
DEVELOPMENT
EMBRYONIC ORIGIN
REGION
Parotid gland primordia (anlage)
5th to 6th week
Ectoderm Labiogingival sulcus
Submandibular gland primordia
6th week Endoderm Hyoid arch
Sublingual gland primordia
7th to 8th week
Endoderm Linguogingival sulcus
Intraoral minor salivary glands
3rd month
Development of Salivary Glands
BudsEpithelial cords
Terminal bulbs
Form clefts
Branches
Repeat process
AGE CHANGES
Age Changes
the aging salivary glands are known to undergo structural changes
The lobule structure becomes less ordered The acini vary more in size and eventually
atrophy Interlobular ducts become more prominent and
the percentage of fibroadipose tissue increases
Age Changes
Changes in the salivary glands (submandibular,parotid (less) and minor salivary glands) Shrinkage of cells Dilation of ducts Oncocytic transformation Increased adiposity Fibrosis Focal microcalcifications with obstruction Chronic inflammation
CLINICAL CONSIDERATIONS
Mucoceles
CAUSE: trauma to excretory ducts of the minor glands which allows the spillage of mucus into the surrounding connective tissue
PHYSIOLOGIC MANIFESTATION: formation of painless, smooth surfaced, bluish lesions
TREATMENT:
self-limiting (acute) or
surgery (chronic)
Mucocele
Ranulas Type of mucocele CAUSE: blocked sublingual gland ducts PHYSIOLOGIC MANIFESTATION: Unilateral,
soft-tissue lesions, often with a bluish appearance. Vary in size and may cross the midline of the
mouth and cause deviation of the tongue TREATMENT:
self-limiting (acute)
surgery (chronic)
Ranula
Sialolithiasis
CAUSE: inactivity of the glands Metabolic conditions that promote salt precipitation in
the glands Predisposing factors: dehydration and poor oral
hygiene PHYSIOLOGIC MANIFESTATION: formation of
caliculi TREATMENT: massaged out by a specialist,
surgery, antibiotics
Sialolithiasis
Necrotizing Sialometaplasia
UNKNOWN CAUSE Possible etiologic agent: smoking, trauma, vascular
disease PHYSIOLOGIC MANIFESTATION: uncommon
benign lesion and inflammatory condition that affects salivary glands, usually the minor salivary glands
TREATMENT:
resolves spontaneously,
self-limiting
Necrotizing Sialometaplasia
Mumps
Aka. epidemic parotitis (viral) Occurs usually during childhood CAUSE: paramyxovirus that infects the parotid
glands PHYSIOLOGIC MANIFESTATION: inflammation
of the parotid glands located on either side of the face
TREATMENT: warm compress,
warm, salt water rinses, antibiotics,
surgery, anti-inflammatory
medications
Mumps
Salivary Gland Neoplasm
Aka. Salivary gland cancer CAUSE: rapid cell growth of the salivary gland PHYSIOLOGIC MANIFESTATION: present as
painless, slow-growing masses TREATMENT: radiation therapy, chemotherapy
Salivary Gland Neoplasms
Irradiation Reaction (Xerostomia) subjective complaint of dry mouth due to a lack
of saliva CAUSE: tumoricidal doses of ionizing radiation,
excessive clearance or breathing through the mouth, hyposalivation (decreased saliva production)
PHYSIOLOGIC MANIFESTATION: dry oral mucosa
TREATMENT: frequent sips of water and frequent mouth care
Xerostomia
THE END
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