Endo: Pancreas L6

Question 1

what is the exocrine role of the pancreas?

what % is exorcine function?

Answer 1

aids digestion via secretion
( cont bicarbonate & rich in digestive and lytic enzymes?

85% exocrine

Question 2

what is endocrine secrtion?

Answer 2

directly into blood without gut

Question 3

what % of pancreas tissue is endocrine?
where is this?
what are the cell types?

Answer 3

2%

• in Islets of Langerhans
• alpha= glucagon
• beta= insulin
• delta= somatostatin

Question 4

what is the structure of insulin?

HOW IS IT FORMED

Answer 4

• 2 chains (A and B) form precursor PROINSULIN
• Proinsulin packaged into early granules with Zn2+ and PROTEASE
• cleaved, binds with Zn2+ to form mature granule
• C-peptide joins with mature

Question 5

role of insulin

Answer 5

• stimulates production of glycogen, lipid and protein
• binds to plasma membrane receptor (linked to tyrosine kinase)
• inc cell uptake of glucose via stimulation of GLUT4
• inc uptake of aa

Question 6

what causes diabetes insipidus?

Answer 6

problems with ADH, allows too much urine to be produced

Question 7

glucagon acts via what>

Answer 7

GPCR and cAMP signalling

Question 8

where are the 2 places somatostatin is released from?

whatis its role?

Answer 8

• pancreas
• hypothalamic PARVICELLULAR neurones (decrease growth hormone secretion)
• role: inhibit insulin and glucagon, prevent exaggerated responses
• secreted after meal or if inc duodenal acid
• if v high conc, inhibits all GI functions ( O can be used as treatment for life threatening diarrhoea that is associayed with GIT tumours)