This document discusses the histology of salivary glands. It describes that salivary glands are exocrine glands that secrete their products through ducts. The basic functional unit of salivary glands is the terminal secretory unit called acini, which can be serous, mucous, or mixed. Serous acini contain protein secretory granules and mucous acini contain mucin secretions. Saliva produced by acini passes through a network of progressively larger ducts including intercalated ducts, striated ducts, and excretory ducts on its way to the oral cavity. The major salivary glands, parotid, submandibular,

1. SALIVARY GLANDS : HISTOLOGY
DR D B PATIL

2. GLANDS
 Gland is an organ in body that synthesizes substance
for release of substances such as hormones often into
bloodstream(endocrine gland) or into cavities inside
body or its outer surface (exocrine gland)

3. CLASSIFICATION OF GLANDS :
 Endocrine glands — are glands that secrete their
products and lack duct system
 Exocrine glands — secrete their products through
duct or directly onto apical surface, glands in this
group can be divided into three groups :

4. EXOCRINE AND ENDOCRINE GLANDS

5. CLASSIFICATION GLANDS
 Apocrine glands —
(e.g.- sweat gland)
 Holocrine glands —
 (e.g., sebaceous glands)
 Merocrine glands —
 (e.g., salivary glands)

7. The type of secretory product :
— secrete watery, often protein-rich Serous glands
product
product, rich Mucous glands — secrete viscous
in carbohydrates (e.g.- glycoproteins)
 Sebaceous glands — secrete lipid product

8. SALIVARY GLANDS
CONSIST :
STROMA-
CAPSULE , SEPTA, BLOOD VESSELS, NERVES
PARENCHYMA-
SECRETORY
DUCTS

9. STRUCTURE OF TERMINAL SECRETORYUNITS
 The basic functional unit of a salivary gland is the terminal
secretory unit called ACINI.
 Acinar cells of Salivary Glands are classified as :-
SEROUS ACINI MUCOUS ACINI MIXED ACINI
PRODUCE THIN PRODUCE MORE BOTH SEROUS &
WATERY SECRETION VISCOUS MUCUS MUCOUS ACINI;
SECRETION MUCOUS HAVE CAP OF
SEROUS ACINI , KNOWN
AS SEROUS DEMIUNES

12. ACINI
 Rest on basement
 Arranged in single layer
 Intercellular spaces of apical ends of cells separated
from lumen by Junctional complexes
 Junctional complexes hold cells together in acini
 Regulate permeability
 Myoepithelial cells are located on surface of acini

13.  Central lumen have a star shaped morphology
 It continues via fine series of tubes which constantly
merges with each other and grow larger eventually to
merge into main excretory duct
 Mucous acini have larger lumen than serous acini
 Intracellular junctions are present in mucous whereas
absent in serous acini

14. SEROUS ACINI Serous acini are protein secreting
cells
 Structure
 Pyramidal with broad base on
basement membrane
 Apex faces lumen
 Spherical nucleus placed at basal
region, occasionally binucleated
 (Lumen is not usually visible at light
microscope level)

15.  Cytoplasm
 Apical cytoplasm shows accumulation of secretory granules
 Basal cytoplasm is packed with
 Parallelly stacked RER, placed basal and laterally to
nucleus
 Free Ribosomes
 Golgi apparatus
 Mitochondria
 Lysosomes

16.  Secretory granules
 Located in apical cytoplasm
 Dense core or twisted skin like structure with lighter matrix
 Granules are zymogen granules i.e. storage of protein
secreting cells
 Mature granules- Dense
 Immature granules- Pale

17. MUCOUS ACINI
 Mucous acini are mucin secreting
cells
 Structure
 Tubular configuration
 Round profiles surrounding
central lumen of larger size than
serous end pieces
with
 Apex of cell appears empty
 Have serous associated
them in form of demilunes.

18. forming
 Cytoplasm
 Thin strands
trabecular network
 Appears like thin rim,
compressed against base of cell
 Apical cytoplasm has large
amount of secretory products
(mucin)
 Mucin compresses nucleus and
ER against cell membrane

19. MYOEPITHELIAL CELLS
 Contractile cells associated with secretory end pieces and
intercalated ducts
 Stellate shaped with flattened nuclei, scanty cytoplasm, long
branching processes
 Intercalated ducts have fusiform shape and elongated processes
 These cells lies between basal lamina and joined to each other by
desmosomes

20. DUCTS

21. DUCTS
 Ductal system is varied network of tubules that progressively
increase in diameter
 Begins from secretory end pieces to oral cavity
 Ducts are for passage of saliva; it actively participates in
production and modification of saliva

22. DUCTS
Intercalated ducts
Striated ducts
Excretory ducts

23. INTERCALATED DUCTS
 Primary saliva produced by secretory end pieces passes first
through it
 First cell of duct is adjacent to end pieces, lumen is continuous
with lumen of intercalated duct
 Lined by simple cuboidal epithelium, myoepithelial cell bodies
 Diameter of duct is smaller than end pieces but their lumen is
larger than end pieces

25.  Constitute largest portion of duct system
 Located within lobules of duct
STRIATED DUCTS

26.  Overall diameter of duct is
greater than secretory end
pieces
 Lumen larger than those of
secretory end pieces and
of primary
intercalated ducts
 Function
 Modification
saliva
secretion Reabsorption and
of electrolytes

27. EXCRETORY DUCTS
 Ducts are larger in diameter
than striated ducts
 located in connective tissue septa
between lobules of gland
 Have psuedostratified epithelium
with columnar cells
 Scattered mucous (goblet) cells
may be present
 Structure similar to striated
ducts

33. SUBLINGAUL GLAND

40. PAROTID GLAND

45. SUBMANDIBULAR GLAND

50. APPLIED ASPECT
PLEOMORPHIC ADEMONA
MUMPS
SIALORHIA
XEROSTOMIA
SIALOGRAPHY
FROIN SYNDROME