Endocrine System Red stuff Flashcards
what are the four classes of chemical messengers
autocrine, paracrine, neurotransmitter, endocrine
what do autocrine chemical messengers act on
the cell from which they are secreted
what do paracrine chemical messengers act on
locally
what do neurotransmitters act on
adjacent cells
what do endocrine chemical messengers act on
secreted by endocrine glands and into blood stream
how are the endocrine and nervous systems similar?
both use brain, may use same chemical messenger as neurotransmitter and hormone(epinephrine), the two systems are cooperative(innervation)
how are the endocrine and nervous systems different?
mode of transport, response speed, duration of response, amplitude(endocrine) vs. frequency(nervous)
how does a higher concentration of hormones affect amplitude?
increases response
the length of time it takes for half a dose of substance to be eliminated from circulatory system is called
half life
regulates activites to stay at a constant rate through time, usually lipid soluble is associated which what half life
long half life
water soluble hormones that have rapid response is associated with what half life
short half life
hormones communicate with target cells by
receptors
when hormones dissolve in blood plasma and are transported in unbound state to shorter half life bc they are subject to degradation by enzymes or filtration kidneys
distribution
what kind of hormones travel with binding protiens?
lipid soluble
what kind of hormones are large hormones dissolved in plasma and small hormones are bound by protiens?
water soluble
maintenance of relatively constant concentration of hormone
chronic hormone secretion
rapid increase of hormone in short time due to specific stimulus
acute hormone secretion
increase and decrease hormone secretion constantly
episodic (cyclic) hormone secretion
three ways to control hormone secretion
humoral, neural, hormonal
cells that respond to these stimuli have receptors for substances in the blood
humoral stimuli
neurons release either stimulatory or inhibitory neurotransmitters
neural stimuli
endocrine organ can stimulate or inhibit another endocrine organ
hormonal stimuli
most hormones have what kind of feedback loop
negative
how do hormones exert their effects
binding to receptors
a drug that binds a hormone receptor and activates it
agonist
drug that binds a hormone receptor and blocks activation
antagonist
after cells are exposed to a hormone and the rate at which receptors are synthesized decreases is called
down regulation
some stimuli cause an increase in the synthesis of receptors for a hormone, increasing sensitivity to hormone
up-regulation
what are the two types of receptors
nuclear receptors, membrane-bound receptors
lipid soluble hormones bind to
nuclear receptors
water soluble hormones bind to
membrane bound receptors
