2: Lecture 7

Question 1

2 Types of Glands in Pancreas and functions

Answer 1

1) Exocrine glands–>secrete digestive enzymes into intestinal lumen
2) Endocrine glands–>secrete hormones into circulation, found in islets of Langerhans

Question 2

Function of alpha cells in islet of Langerhans

Answer 2

Secrete glucagon–>stimulates glycogenolysis by liver during fasting or exercise–>liver releases glucose into bloodstream
20% of endocrine cells

Question 3

Function of beta cells in islet of Langerhans

Answer 3

Secrete insulin, C-peptide, and amylin
Released in response to increase in blood glucose to stimulate glucose uptake by cells
70% of endocrine cells

Question 4

Function of delta cells in islet of Langerhans

Answer 4

Release somatostatin–>inhibits synthesis of growth hormones
10% of endocrine cells

Question 5

Formation of Insulin

Answer 5

Synthesized as preproinsulin–>cleavage of SP chain and folding–>proinsulin (has C-peptide, and A and B chains)–>release of C peptide in Golgi–>mature insulin
Mature insulin has 2 chains: A and B chain linked by disulfide bridges

Question 6

How is mature insulin secreted?

Answer 6

As a complex of Zn2+ and insulin aggregated into dimers and hexamers into vesicles with amylin and C-peptide

Question 7

Type 2 Diabetes

Answer 7

Associated with genetic and metabolic defects that impacts glucose metabolism, insulin secretion or insulin action in tissues
Higher than normal baseline levels of blood glucose
Insulin release in response to glucose is delayed

Question 8

Main consequence of Diabetes

Answer 8

Hyperglycemia (chronically high blood glucose levels)–>causes damage to blood vessels triggering plaques and inflammation

Question 9

Criteria for Diabetes

Answer 9

Elevated glucose levels
Hemoglobin A1C (glycated hemoglobin)

Question 10

Testing for hemoglobin A1C

Answer 10

A1C (glycated hemoglobin) has to be greater of equal to 6.5%
A1C is glucose modified hemoglobin

Question 11

Testing for elevated glucose levels

Answer 11

Test for FPG (fasting plasma glucose)
2 hour plasma glucose
Random plasma glucose (greater or equal to 200 mg/dL)

Question 12

Test for FPG

Answer 12

Fasting plasma test–>no caloric intake for at least 8 hours
Fasting plasma glucose has to be greater or equal to 126mg/dL

Question 13

Test for 2 hour plasma glucose

Answer 13

Oral glucose tolerance test
Use glucose load of 75g evaluate acute response
2 hour plasma glucose has to be greater or equal to 200 mg/dL