Chapter 18 [ EXAM #2 ] Flashcards
function: supersystem
nervous and endocrine system
release chemicals, bind receptors
goal: supersystem
coordinate body functions and preserve homeostasis
describe: endocrine system
endocrine cells secrete chemical hormones into blood
blood reached target cells with hormone receptor
NS vs. ES communication method
NS = impulses cause NT to release locally
ES = hormones secreted into blood to distant cells
NS vs. ES target cells
NS = post-synaptic neurons, muscles, and glands
ES = any body cell with receptor far from release
NS vs. ES response time
NS = rapid msec -> sec
ES = slow sec -> min -> hour
NS vs. ES stimulation effect
NS = stimulation, inhibition
ES = growth, reproduction
NS vs. ES range of effect
NS = local and specific
ES = widespread
NS vs. ES duration of response
NS = short term and stops with stimulus removal
ES = long term and continues after stimulus removed
function of exocrine glands
secrete non-hormonal products onto a surface
function of endocrine glands
secrete hormone products into surrounding body fluids
what are hormones
circulating chemical messengers
circulation of hormones
hormones come from secretory cells and enter interstitial fluid into blood
how long do hormones circulate
hours
how are hormones inactivated
enzymes or liver
how are hormones eliminated
kidneys
what kind of solubility are steroid hormones
steroid hormones are lipid soluble
what are steroid hormones made from
steroid hormones are made from cholesterol
where do steroid hormones end up
steroid hormones enter the nucleus
what kind of solubility are protein hormones
protein hormones are water soluble
how long are protein hormones
variable lengths (9 -> 198 aa’s)
what is a prohormone
prohormones get activated into protein hormones
what kind of solubility are biogenic amines
water soluble (except thyroid hormone)
if something is water soluble then it is…
lipid insoluble
if something is lipid soluble then it is…
water insoluble
hormones travel through the blood either one of two ways…
free (water soluble)
protein-bound (lipid soluble)
what does blood concentration reflect
rate of synthesis and release
rate of inactivation or elimination
what are two causes of altered rate in the inactivation or elimination in blood concentration
enzyme degradation
removal by kidneys
do all hormones have immediate effects?
nope.
do all hormones have short-term or long-term effects
some short-term, some long-term
effects of hormones on plasma membrane
effects permeability
opens/closes ion channels
do hormones increase or decrease enzyme synthesis
hormones increase enzyme synthesis
mechanism of lipid soluble hormones
enters target cell
activates receptor-hormone complex, alters gene expression
specific proteins are created
new proteins alter cell’s activity
mechanisms of water soluble hormone
binds to plasma membrane receptor
starts multi-step transduction pathway
signals G protein
what is up-regulation
more receptors due to decreased hormone levels
what is down-regulation
less receptors due to elevated hormone levels
what are three things that influence hormone-receptor interaction
blood levels of hormone
of receptors
affinity (strength) of binding between hormone and receptor
negative feedback of hormone release
opposes original stimuli
hormonal stimuli
release of a hormone in response to another hormone
humoral stimulation
release of a hormone in response to change in levels of nutrients or ion in blood
nervous system stimulation
release of hormone in response to stimulation by NS
