Pancreas Flashcards
What is the term for islands of endocrine cells within exocrine tissue?
Islets of langerhands
(secrete digestive enzymes)
What do the following cells secrete?
𝛃 cells (60% of endocrine cells)
𝛂 cells (25% of endocrine cells)
𝛅 cells
𝛄 cells
𝝐 cells
𝛃 cells = Insulin, Amylin
𝛂 cells = Glucagon
𝛅 cells = Somatostatin
𝛄 cells = Pancreatic polypeptide
𝝐 cells = Ghrelin
What hormones inhibit digestive function/ suppress appetite?
Amylin (acts on CNS, suppresses appetite)
Somatostatin (inhibits digestive function)
Pancreatic polypeptide (reduces appetite/ food intake)
What is the role of Ghrelin?
Appetite stimulating
Preproinsulin is converted to proinsulin which is cleaved in the granules to what?
Insulin + C-peptide (1:1 ratio)
(C-peptide is more reliable measurement for assessing insulin use in DM pts due to longer half life)
Glucose stimulates insulin release via what process in beta cells?
Excitation-secretion coupling
What is necessary for the facilitated diffusion of glucose across cell membranes?
GLUT2
In the process of insulin release, glucose and PO4 yield glucose-6-phosphate which is then oxidized to form what?
ATP
What is the role of ATP in the release of insulin?
Closes K+ channels = decreased K+ depolarizes cell membrane
(This leads to voltage- gated Ca channels opening and Ca entering the cell)
In the insulin release process, once Ca enters the beta cells, what does this trigger?
Triggers exocytosis of insulin vesicles = insulin secreted into circulation
What are the 3 primary effects of insulin?
- Affect energy stores
- Recruits GLUT-4 to cell surface
- Stimulates MAP kinase pathways
Excess insulin can lead to hypoglycemia which can then ultimately lead to what?
Depressed brain function/ LOC
How does insulin affect energy storage in carbs, lipids, and proteins?
Promotes storage
(decreases blood glucose, fatty acids, and AAs)
In what tissues does the insulin dependent transporter GLUT-4 exist?
Adipose and resting muscle cells
Where are GLUT 1, 2, and 3 proteins located?
GLUT1 = BBB
GLUT2= kidney/ intestine
GLUT3= neurons
How do you treat an insulin OD?
Exogenous sugar
……. or should i say……. a sugary snack
How do you treat reactive hypoglycemia (beta cells release too must insulin in response to glucose)?
Control by limit of dietary cards, DO NOT treat with exogenous sugar
What is the most common endocrine disorder?
DM = high blood surgar levels over a prolonged period