W27/L2 Flashcards
(21 cards)
The vast majority of the pancreas has what function?
Exocrine
What percentage of the pancreas has endocrine activity?
2%
What 4 cells are found in the Islets of Langerhans?
Alpha
Beta
Delta
Theta
Beta cells make up what proportion of cells in the Islet?
80%
Alpha cells make up what proportion of cells in the Islet?
10%
Delta cells make up what proportion of cells in the Islet?
5%
Theta cells make up what proportion of cells in the Islet?
5%
What do beta cells produce?
Inuslin
Amylin
What do alpha cells produce?
Glucagon
What do delta cells produce?
Somatostatin
What do theta cells produce?
Pancreatic polypeptide
Where in the Islet are the beta cells found?
In the centre
Where in the Islet are the alpha, delta, and theta cells found?
Around the mantle
What are the components of preproinsulin?
Signal protein, A, B and C petides
What are the components of proinsulin?
A, B and C peptides
What converts preproinsulin to proinsulin and how?
Prohormone convertase 2 cleaves the signal protein
What are the components of insulin?
A and B peptides
What converts proinsulin to insulin and how?
Prohormone convertase 1 cleaves the C protein
Insulin secretion occurs in 2 phases - what are they?
1st phase - lasts 2-5 minutes and is a sharp rise in secretion
2nd phase - lasts the duration of the stimulus and is a prolonged secretion
What is thought to explain the sharp rise in insulin levels in phase 1?
Release of insulin from vesicles already near the cell surface.
What are some of the exocrine products of the pancreas?
Bicarbonate Amylse Trypsin Chymotrypsin Carboxypeptidase
