Diabetes Part 1.PP slides 1-43 Flashcards
Where is the pancreas?
- The pancreas located deep to the stomach
- Stretches across the abdomen with
–Head adjacent to the duodenum
–Tail adjacent to the spleen
Another picture of the pancreas
What two major types of tissues make up the pancreas and what do they secrete?
- Acini- secrete digestive juices into the duodenum (exocrine)
- Islets of Langerhans- secrete insulin and glucagon directly into the blood (endocrine)
4 types of cells contained in the Islets
How are they distinguished from one another?
- α-
- β-
- δ-
- PP
–Types are distinguished from one another by their morphological and staining characteristics
3 fun facts about β-cells
(not really fun, but let’s pretend)
- Constituting about 60% of all the cells of the islets
- Lie mainly in the middle of each islet
- Secrete insulin and amylin (inhibits insulin secretion, any other effects unknown)
How many α-cells are in the Islets roughly? What do they secrete?
- about 25% of the total
- Secrete glucagon
How many δ-cells are in the Islets roughly? What do they secrete?
- About 10% of the total
- Secrete somatostatin
How many PP cells are in the Islets roughly? What do they secrete?
- Very few in number
- Secretes a hormone of uncertain function called pancreatic polypeptide
What does PP stand for in PP cells?
Pancreatic Polypeptide
Point about communication among cells in pancreas
The close interrelations among these cell types allow cell-to-cell communication and direct control of secretion of some of the hormones by the other hormone
What does insulin inhibit?
glucagon secretion
What does amylin inhibit?
insulin secretion
What does somatostatin inhibit?
the secretion of both insulin and glucagon
What is Diabetes Mellitus?
Chronic disorder caused by either deficient insulin, or defective insulin action
–Hyperglycemia
–Disruption of metabolism of carbohydrates, fats, and proteins
Diabetes Mellitus is the leading cause of what 3 things?
- ESRD (end stage renal disease)
- blindness
- non-traumatic amputation of LE
*has cascading effect on other diseases
What are the effects of insulin on the metabolism?
- Increase carbohydrates storage as glycogen mainly in the liver and muscles
- Increase amino acid uptake and protein synthesis
- Increase fatty acid storage in adipose tissue
Basic explanation of how insulin is involed in Type 1 and 2 Diabetes
- Type I DM – little or no insulin produced
- Type 2 – defective insulin and/or impaired cell receptor binding of insulin
What happens with carbohydrate metabolism with glucose uptake in the muscle?
–Activity – increase membrane permeability to glucose during moderate or heavy exercise
–Carbohydrate consumption - Insulin can increase the rate of transport of glucose into the resting muscle cell by at least 15-fold
What is the purpose of GLUT1 transporters in the brain?
Brain has GLUT1 transporters so glucose uptake in brain not directly insulin dependent