kin lecture 34 Flashcards
What are the endocrine cells of the pancreas?
Islet cells
What do the islet cells do?
Secrete hormones
What are the exocrine cells of the pancreas?
Acini cells
What do the acini cells do?
Make pancreatic juice that empties into pancreatic duct
What is inside of the pancreatic duct?
Alpha cells make 17% of the pancreatic islet and make glucagon; Beta cells make up 70% and make insulin; Delta cells secrete somatostatin; F cells secrete pancreatic polypeptide
Is the pancreatic islet highly vascularized?
Yes
What does glucagon do?
Raises blood glucose through liver glycogen breakdown and gluconeogenesis
What does insulin do?
Lowers blood glucose by increasing glucose uptake, increasing synthesis of glycogen, triglycerides, and proteins
What does somatostatin do?
Inhibits secretion of insulin and glucagon, slows GI absorption
What does pancreatic polypeptide do?
Inhibits somatostatin, gallbladder contraction, secretion of pancreatic digestive enzymes
What happens when blood glucose levels are too low?
Low blood glucose (hypoglycemia) stimulates alpha cells to secrete glucagon; Glucagon acts on hepatocytes to convert glycogen into glucose and form glucose from lactic acids and certain amino acids; Glucose released by hepatocytes raises blood glucose levels to normal
What happens when blood glucose continues to rise?
If blood glucose continues to rise, hyperglycemia inhibits release of glucagon
What happens when blood glucose is too high?
High blood glucose (hyperglycemia) stimulates beta cells to secrete insulin; Insulin acts on body cells; Blood glucose level falls; If blood glucose continues to fall, hypoglycemia inhibits release of insulin
How does insulin act on body cells?
Insulin acts on body cells to accelerate diffusion of glucose into cells, speed conversion of glucose into glycogen, increase uptake of amino acids and increase protein synthesis, speed synthesis of fatty acids
What hormones from the hypothalamus are involved in the body’s stress response?
CRH, GHRH, TRH
What hormones from the anterior pituitary are involved in the body’s stress response?
TSH, hGH, ACTH
How do signals from the nervous system act on the stress response?
Fight or flight responses (increased heart rate, constriction of skin and viscera blood vessels, dilation of blood vessels from lung, heart, brain, skeletal muscles, contraction of spleen, sweating, decrease in digestive activities, and water retention and elevated blood pressure); Also affect the adrenal medulla which makes epinephrine and norepinephrine to aid in stress response
How do the anterior pituitary gland hormones impact the body’s stress response?
Have a resistance reaction: Impact the adrenal cortex, liver, and thyroid gland
What is the adrenal cortex stress response?
Lipolysis, gluconeogenesis, protein catabolism, sensitized blood vessels, reduced inflammation
What is the liver’s stress response?
Lipolysis, Glycogenolysis
What is the thyroid hormones stress response?
Makes T3 and T4 which increase use of glucose to produce ATP
