HISTOLOGY OF SALIVARY

GLANDS

ByDr. Hanan Said Seleem

INTRODUCTION Three major paired

salivary glands: the submandibular, the sublingual and the parotid glands.

Exocrine glands that produce saliva.

branched tubuloalveolar glands

The minor salivary glands are located in submucosa of different parts of oral cavity.

STRUCTURE OF SALIVARY GLANDS

Salivary gland consists of: Stroma parenchyma

THE STROMAConsists of: Capsule of CT covering the gland Trabeculae or septae arise from

capsule divide the gland into lobes & lobules

Reticular tissue

THE PARECHYMA

Secretory units Duct system

SECRETORY UNITS(SALIVARY ACINI) Acinus is a group of cells surrounding a

lumen Cells lie on a basement membrane BUT

separeted from it by basket cells. There are three types of acini

Serous acinusMucous acinusMucoserous acinus

Serous acinus Mucous acinousSmall diameter & narrow lumen Large diameter & wide lumen

Deeply stained Paler & lightly stained

Cells are pyramidal with indistinct boundaries

Cells are irregularly cuboid with distinct boundaries

Nuclei are rounded & nearer to centre

Flattened & basal in position

Cytoplasm is deeply basophilic (RER) with acidophilic zymogen granules in the free border

Pale cytoplasm, foamy or vacuolated ( mucin dissolve during preparation)

Basket cells are less numerous More numerous

Secretion is serous fluid Mucus secretion

Mixed acinus ( muco-serous):

Mucous acinus which is capped by serous cells forming a serous demilune called crescent of Gianuzzi

Secretion of demilune passes to the lumen through canaliculi between the mucous cells.

BASKET CELLS Lie between the secretory cells of the acini

and the BM. Contain actin & myosin so called

myoepithelial cells Their contraction squeez the secretion out

into the duct system

THE DUCT SYSTEMIncludes: Intercalated (intercalary) ducts arise from secretory units lined

with flat or low cuboidal. Several intercalated ducts merge with each other to form striated

ducts, composed of a single layer of cuboidal to low columnar cells, The basolateral membranes of these cells are highly folded, occupied by mitochondria

Intra- lobular (secretory or salivary) ducts inside the lobules. They take part in secretion. Liend with cubical or columnar cells

Inter-lobular (excretory) ducts in septa between lobules & lined with columnar cells

Inter-lober ducts larger ducts in septa in between lobeslined with psudostratified columnar cells

Main duct union of interlober ducts lined with stratified columnar then st. sq near opening in mouth cavity

PAROTID GLANDS Capsule & septa

are thick, fibrous & well developed

Fat cells accumulate around the capsule

Acini are purely serous

Intralobular ducts are very prominent & extensive

SUBMAXILLARY (SUBMANDIBULAR) Capsule & septa are

thick & fibrous Fat cells present in septa

but less numerous than parotid.

Acini are predominantly serous with some mucous & mixed acini

Intra lobular ducts are very prominent & more extensive than parotid.

SUBLINGUAL GLAND Capsule is thin &

indistinct but septa are well developed

Acini are predominantly mucous with some crescents of Gianuzzi

Intralobular ducts are fewer than thos eof parotid & submaxillary glands.

Thank you