Pancreas and its hormones descriptive notes along with pictures

1. Pancreas and its Hormones
By
D. Joy Merlin

2. Pancreas
• It is a dual function organ situated in the loop of
stomach and duodenum.
• Its exocrine part –digestive enzymes
• Endocrine part – hormones-insulin,glucagon.
• It is made up of islet of langerhans cells.
• Exocrine cells called acini, which are involved in
the synthesis of pancreatic juice.
• It will be helpful in digestion of protein, fat and
carbohydrates in food.

5. Islets of langerhans
• Islets of langerhans, which contains 3 types of
cells:
– The alpha, α
– The beta, β
– The gamma, γ
– The delta, δ

6. • In human pancreas, about 2millions islets are
there.
• 65% - beta cells – responsible for the synthesis
of insulin.
• 25 % - alpha cells- responsible for the synthesis
of glucagon.
• 5 to 10% - delta – secrete somatostatin.
• In addition, other type of cells- PP cells- secrete
Pancreatic Peptide.
• The hormones secreted in islets directly oured
into the blood stream.

7. Insulin
• Insulin is a small protein hormone secreted by
beta cells of islets of langerhans.
• In 1922, Banting and Best, isolated insulin from
pancreas for the first time.
• It composed of 2 polypetides, A and B chains
which are held together with di-sulhide bonds.
• The chain A composed of 30 aa’s
• The chain B composed of 21 aa’s

8. • Thus, insulin has 51 aa’s with M.wt:
6000 daltons.
Biosynthesis of Insulin
• Synthesized by direct transcription and
translation process of gene.
• Precursor of insulin is Proinsulin, synthesized in
microsomal fraction of ancreatic beta cells as a
long chain with M.wt: 9000 da.
• Post-translational modification gives 31aa C-
petide by proteolytic enzyme treatment.

10. • Insulin (proinsulin) stored in granules of Golgi
body, which is resent in Beta cells.
• It will be released when it is needed.

13. Pathophysiology
Diabetes Mellitus
• This condition caused by deficiency in the
secretion or action of insulin.
• "Diabetes Mellitus" means "excessive
excretion of sweet urine"
• Nearly 10% of Indian population shows some
degree of abnormality in glucose
metabolism.

14. • Two major classes of DM:
1. Type l diabetes Mellitus, or insulin-dependent
diabetes Mellitus (IDDM).
2. Type ll diabetes Mellitus, or non-insulin-
dependent diabetes Mellitus (NIDDM), also
called as resistant diabetes.
• In Type 1 diabetis the disease begins early in
life and quickly becomes severe.
• It is due to inability to produce sufficient
insulin.
• IDDM requires insulin therapy and careful
lifelong control of the balance between
dietary intake and insulin dose

15. • Characteristic symptom of Type 1 (and type 2)
diabetes are excessive thirst and frequent
urination (polyuria) leading to intake of large
volumes of water (polydipsia).
• These symptoms are due to the excretion of
large amounts of glucose in the urine, a
condition known as glycosuria.
• Type 2 diabetes is slow to develop (typically in
older, obese individuals ) and the symptoms are
milder and often go unrecognised at first.

16. Hypoglycemia
• It is defined as syndrome characterized by Low
plasma glucose and associated group of
symptoms.
• In infant the hypoglycemia that is its plasma
glucose concentration is less than 25 mg per
100ml of blood.
• In adults two groups of symptoms occur
depending upon whether the hypoglycemia is
acute or chronic.