Chapter 17 - The Endocrine System (finish)

Adrenal glands are located

superior to each kidney (adrenal cortex is outer, adrenal medulla in inner)

Adrenal cortex produces

mineralocorticoids, glucocorticoids, androgens

Glucocorticoids function

anti-inflammatory, provide resistance to stress by increasing lipolysis and gluconeogenesis (which provides nutrients in the bloodstream to make the extra ATP required in stressful situations)

Glucocorticoids are regulated by

CRH (corticotropin releasing hormone) from the hypothalamus stimulates the release of ACTH (adrenocorticotropic hormone) from the anterior pituitary gland, which stimulates the release of cortisol from the adrenal cortex

High levels of cortisol

feedback and inhibit the release of ACTH and CRH

ACTH is secreted as

prehormone called POMC, which is processed to produce ACTH and MSH

MSH is

melanocyte stimulating hormone, which stimulates the production of melanin (black pigment)

Hypersecretion of cortisol condition

Cushing's disease

Cushing's disease symptoms

distribution of body weight changes (heavy trunk and thin extremities), "moon face", "hanging abdomen", poor wound healing due to anti-inflammatory properties

Cushing's disease treatment

removal of tumor

Hyposecretion of cortisol condition

Addison's disease

Addison's disease symptoms

weakness, nausea, weight loss, hypotension, elevated CRH causes hyperpigmentation

Gonadocorticoids provide

male and female sex steroids

Adrenal medulla secretes

Epinephrine and Norepinephrine (sympathetic)

Hypersecretion of epinephrine can be due to

pheochromocytoma (tumor that releases epinephrine, increases fight or flight, BP, respiration, sweating, etc)

Pancreas exocrine and endocrine secretions

exocrine: digestive juices, endocrine: insulin and glucagon

Insulin

peptide hormone, secreted from beta cells after a meal when blood glucose levels are high

Insulin increases

protein synthesis, glycogen synthesis (glycogenesis), and lipid synthesis (stores nutrients)

Insulin lowers

blood glucose levels, by stimulating amino acid glucose uptake into cells from blood

Glucagon

peptide, secreted from alpha cells between meals when blood glucose levels are low

Glucagon stimulates

gluconeogenesis, breakdown of glycogen (glycogenolysis) and triglycerides, raises glucose levels in the blood

Diabetes mellitus

high blood glucose levels, symptoms include increased thirst, increased hunger, increased urination

Type 1 diabetes

autoimmune, caused by inadequate insulin levels, treatment includes insulin injections

Type 2 diabetes

typically affects individuals who are overweight, genetic predisposition, insulin levels normal, treatment includes diet, exercise, glucose lowering medication (metformin)

Uncontrolled diabetes can lead to

kidney disease, nerve damage, and higher risk of stroke and heart attack