HISTOLOGY OF SALIVARY GLANDS Dr. Sobia Ibrahim Assistant Professor A KEMU
Jan 29, 2016
HISTOLOGY OF SALIVARY GLANDS
Dr. Sobia IbrahimAssistant Professor Anatomy,KEMU
Saliva is produced by Three major salivary glandsParotidSubmandibularSublingualNumerous minor salivary glands
Saliva is a hypotonic watery secretion It contains mucous,Enzymes,Secretory antibodies, Inorganic salts.Daily production is 600-1500ml in human
GENERAL STRUCTURE OF SALIVARY GLANDS
STROMA
Capsule
Septa
Blood vessels & nerves
Ducts
Lobule
PARENCHYMA
Accini
Duct system
Each gland is surrounded by a connective tissue capsule
From capsules, multiple septae are thrown inwards to divide the parenchyma into incomplete lobules
Within each lobule many secretory acini are surrounded by fine loose C.T .
Blood vessels, lymphatic vessels, nerves and excretory ducts travel through septa.
PARENCHYMA
Glands are tubuloacinar variety
Acini consists of secretory cells which have a lumen in middle going to duct
Serous, mucous or mix.
Myoepithelial cells lie between plasmalemma and basal lamina of secretory cells
MUCOUS & SEROUS ACCINI
DUCT SYSTEM INTERCALATED DUCTS
Lined by cuboidal epithelium
STRIATED DUCT Lined by columnar cells
& show Radial striations INTERLOBULAR/ EXCRETORY DUCTS- in
CT septa Proximally-
pseudostratified/stratified cuboidal
Distally – stratified columnar
MAIN DUCT Non keratinized stratified
squamous epithelium
PAROTID GLAND BRANCHED ACCINAR gland
SEROUS
Striated & intercalated
ducts in parenchyma
Interlobular duct in CT
septa
Plasma cells present in CT
septa
Secretory products has:
Amylase
Proline- rich protien
which has
calcium binding
properties
SUBMANDIBULAR GLAND
BRANCHED TUBULOACCINAR
gland
Predominantly SEROUS
Majority serous accini
Mucous accini with serous
demilunes-10%
Well developed striated ducts
Underdeveloped intercalated
ducts
Secretory products have:
Amylase
Proline rich protiens
Lysozymes
SUBLINGUAL GLAND
BRANCHED
TUBULOACCINAR gland
Predominantly mucous
Serous cells only as
demilunes
Striated & intercalated
ducts not well
developed
Secretory products :
Amylase
Lysozymes
COMPARISON
MINOR SALIVARY GLANDS
Scattered throughout oral mucosa & submucosa
Nonencapsulated
Usually MUCOUS
Exception is von Ebner gland of tongue
Short ducts open on oral mucosa
B lynmphocytes releasing IgA common
MEDICAL APPLICATION
Reduced function of major salivary glands due to
disease / radiotherapy
RESULTS:
◦ Caries
◦ Atrophy of oral mucosa
◦ Speech difficulties
SEROUS CELL
Pyramidal cells. Broad end facing the
basement membrane and narrow end facing lumen.
6-8 in no. Apex has microvilli Basal region has rounded
nucleus. Basal region have
abundant RER (due to which basal region stain basophilic)and mitochondria.
Apical region : zymogen (secretory) granules ,so apical region is acidophilic
Adjacent serous cell joined by junction near apices.
Intercellular canaliculi
FUNCTION: thin and watery secretions
MUCOUS CELL
Tall cuboidal or low columnar cells with basal flattened nuclei.
Apical region has mucinogen granules.
H&E stain mucous poorly so muous cells appear empty.
Well developed golgi apparatus.
E/M: junctional complexes, no intercellular canaliculi.
Cells secrete mucinogen which on contact with water form mucous.