Lecture 21: Endocrine System - Pancreas Flashcards
What hormones does the endocrine pancreas make?
Insulin and glucagon
What makes up 99% of the pancreas
Acini, exocrine digestive cell clusters, that connect the ducts
What makes up 1% of the pancreas
Several million islets of Langerhans
What are alpha cells
Cells that are 20% of islet cells; secrete glucagon
What is glucagon
A hormone that raises blood sugar to maintain normal levels. It acts on hepatocytes to make glycogen to glucose and amino acids into glucose.
What are beta cells
80% of islet cells; secrete insulin
What is insulin
A hormone that lowers blood sugar.
What does the movement of potassium and sodium cause?
Electrical conduction in the nerves and heart when potassium and sodium move between the cells and the blood
What happens when there is excess potassium?
It fatally prevents electrical conduction
What are delta cells and their functions?
Less than 1% of pancreatic cells; secrete somatostatin; inhibits insulin release; slows nutrient absorption in GI tract
What are F cells and their function?
less that 1% of islet cells; release pancreatic polypeptide
Diabetes mellitus means and is what?
“copious sweet urine”; glucose levels are high in the blood
What is diabetes mellitus characterized by?
three “polys”
- polyuria: lots of urine
- polydipsia (very thirsty and drinking lots of liquids)
- polyphagia (lots of eating)
Two main types of diabetes mellitus
Type I and Type II
Type I diabetes
insulin-dependent; 10-20% of cases; aka juvenile-onset diabetes; brittle diabetics; body is becomes allergic to beta cells and starts to destroy them; must have injections of insulin
What do cells use when the person has type I diabetes?
Fatty acids for energy; this results in ketones
what are ketones?
Fatty acid waste that are acidic; they cause the blood to become very acidic; condition is called ketoacidosis.
What is type I diabetes?
A protean disease (a disease that affects every body system)
What is type II diabetes?
Non-insulin-dependent diabetes; maturity-onset diabetes; 80-90% of all cases; target cells are less sensitive to insulin action; treatment includes weight loss, exercise, and diet
What is gestational diabetes?
Happens during pregnancy; is an elevation of blood glucose; problems are the same of Type II diabetes
Patients with high blood sugar and too little insulin?
- symtopms: coma, slow onset, lethargy, confusion, odor of acetone on breath
- treatment: insulin
Patients with low blood sugar and too much insulin
- symptoms: faster onset; confusion/coma, shock, and death; people who overdosed on narcotic drugs have similar symptoms
- treatment: oral or intravenous glucose
What is Zollinger-Ellison syndrome?
Ulcer disease that is caused by a tumor that secretes gastrin in the pancreas and over produces stomach acid. Treated by proton-pump inhibitors to block acid production
What activates the release of glucagon?
Low blood sugar.
What is glycogenolysis?
Process of glucagon acting on hepatocytes to make glycogen into glucose
What is gluconeogenesis?
Process of glucagon acting on hepatocytes to make amino acids into glucose
Processes of insulin
1) increase diffusion speed of glucose into cells and conversion of glucose into storage form, glycogen
2) increases synthesis of proteins from amino acids, fatty acids
3) decreases rate of glycogenolysis and gluconeogenesis
