Chapter 9 - Endocrine system Flashcards
6 major glands
pituitary thyroid parathyroid adrenal pineal thymus
major difference between neurotransmitters and hormones
hormones are secreted into the blood
3 major organs with endocrine function
pancreas
gonads- ovaries/ testes
hypothalamus
2 major mechanisms in hormone
- second messenger protein hormones
2. direct gene activation steroid and thyroid hormones
second messenger
protein hormones cant enter cell hormone
cAMP second messenger
G protein> adenylate cyclase>protein kinases>phosphorylate proteins>altered enzyme activity
direct gene activation
steroid hormones are lipid soluble, so they can diffuse through the cell membrane since the cell membrane is made of fat
target cells
hormones can only influence certain cells. target cell has a receptor for a certain hormone.
control of hormone release
negative feedback.
hormone secretion is triggered by some internal or external stimulus
3 types of endocrine gland stimuli
- humoral
- neural
- hormonal
humoral stimuli
secretion of hormones in direct response to hanging blood levels of ions and nutrients
neural stimuli
nerve fibers stimulate hormone release
hormonal stimuli
hormones stimulate other endocrine organs to release their hormones
pituitary dwarfism
hyposecretion of GH during childhood
gigantism
hypersecretion during childhood