1. HISTOLOGY OF PANCREAS

2. PANCREAS Has exocrine & endocrine functions Parts Capsule
Septa – lobules
Secretions:
Enzymes
Hormones

3. EXOCRINE PANCREAS COMPOUND ACCINAR GLAND Pear shaped accini
5-8 pyramidal cells
Reticular fibers support accini
Inter- lobular CT contains:
Blood vessels
Nerves
Lymphatic

4. EXOCRINE PANCREAS ACCINI Cells have spherical basal nucleus
Basal cytoplasm basophilic – RER
mitochondria
Golgi apparatus
Apical zymogen granules – maximum in fasted person
Centroacinar cells

6. EXOCRINE PANCREAS DUCTS Intercalated ducts NO striated ducts
Large intralobular ducts – high cuboidal epithelium
Interlobular ducts – columnar epithelium
Larger ducts
Main duct

7. SECRETIONS OF EXOCRINE PANCREAS
Proteases (trypsinogen & chymotrypsinogen etc.)
Amylase
Lipase
Nucleases (DNAase & RNAase)

8. MEDICAL APPLICATION ACUTE NECROTIZING PANCREATITIS Proenzyme activated
Digest pancreatic tissue
Causes:
Alcoholism
Gall stones
Trauma
Drugs

9. MEDICAL APPLICATION Extreme malnutrition e.g. kwashiorkor
Atrophy of pancreatic acinar cells
Loss of RER
Digestive enzyme production hindered

10. ENDOCRINE PANCREAS (ISLETS)
Embedded within accini
µm diameter
> 1 million islets
Abundant in tail

11. ISLETS OF LANGERHANS Reticular fibers surround each islet
Small polygonal cells
Cells lightly stained
Arranged in anastomosing cords
Fenestrated capillaries between cords
Autonomic fibers

12. ISLETS OF LANGERHANS CELLS OF ISLETS
A /α cells- glucagon, at periphery
B /β cells- insulin, at center- numerous
D /δ cells- somatostatin, scattered
F /PP cells- pancreatic polypeptide
Enterochromaffin cells- motilin,secretin,
substane -P

13. BLOOD SUPPLY Rich arterial supply Major BV run in interlobular CT
Intralobular BV
Arterioles pass to islets
Extensive capillary network
First supply peripheral cells
Blood from islets pass to supply exocrine tissue
Hormones effect acinar function

15. COMPARISON
PAROTID GLAND
PANCREAS

16. MEDICAL APPLICATION INSULIN DEPENDENT / TYPE I DIABETES (juvenile)
Autoimmune disease
Partial or total destruction of β cells
Lack of insulin
INSULIN INDEPENDENT DIABETES / TYPE II
Adult onset
Associated with obesity
Failure of cell to respond to insulin
TUMOURS OF ISLETS
May secrete anyone of the hormones
May secrete more than one hormone