HISTOLOGY OF SALIVARY
GLANDS
Dr. Sobia Ibrahim
Assistant Professor Anatomy,
KEMU
Saliva is produced by
 Three major salivary glands
 Parotid
 Submandibular
 Sublingual
 Numerous 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
 Proximallypseudostratified/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.