Digestive GL 2
Digestive GL 2
Digestive GL 2
By
Amal Fares
Pancreas
Pancreas
Mixed gland.
Stroma:
▪ Capsule(Thin, Covered by
peritoneum),
▪ Trabeculae (thin)
▪ Reticular network
Parenchyma:
serous
▪ Exocrine portion : (Acini and Ducts),
compound tubulo-alveolar gland.
▪ Endocrine portion: (Islets of
Langerhans).
Exocrine Portion
pancreatic (serous) acini:
▪ Small,with narrow lumen.
▪ Lined with pyramidal cells
▪ Basal basophilic cytoplasm and apical acidophilic
(zymogen granules).
▪ Basal rounded nucleus
Exocrine Portion
Duct system:
▪ Intercalated duct: telescoped inside the
acini, simple squamous cells, inside the
lumen.
▪ Intra-lobular ducts: not apparent.
▪ Inter-lobular ducts: simple cubical
epithelium
▪ Inter-lobar ducts: simple columnar
epithelium
▪ Main duct: simple columnar epithelium
with goblet cells and few
enteroendocrine cells - Joins the common
bile duct to open in the duodenum.
endocrine portion
Islet of langerhans
▪ Pale stained areas
scattered between
deeply stained
pancreatic acini
▪ groups of cells separated
by fenestrated blood
capillaries and
supported by reticular
network.
Islet of langerhans
Beta cells % Alpha cells 15 % Delta cells –10 %
70
Diameter small large large
Position Central peripheral Peripheral
LM Basophilic Acidophilic Granules only
granules. granules. stain with (Ag)
EM rER, G.A., mitochondria, membrane bound secretory
granules.
Function Secrete Secrete Secrete
insulin that Glucagon that somatostatin
decrease increase blood which controls
blood glucose release of insulin ,
glucose glucagon & GH
Islet of langerhans
• C-cells: 3%, few granules, stem or
exhausted cells.
• G-cells: secrete gastrin which stimulate
HCL secretion by stomach.
• Ganglion cells: nerve cells responsible for
autonomic control of islets
• PP cells: secrete pancreatic polypeptide
which reduces pancreatic secretion
Differences between parotid gland
and pancreas
Parotid Gland Pancreas
Number & type 2 Exocrine Single Mixed