Question | Answer |
define gland | an organ that secretes a substance |
describe exocrine glands | secrete substances via ducts to the outside of the body |
describe endocrine glands | secrete hormones directly into blood capillaries |
describe true endocrine glands | produce only hormones |
describe endocrine tissue | tissues found in organs that produce hormones, yet function in other ways as well |
name the 6 true endocrine glands | hypophysis, thyroid, adrenals, thymus, pineal, parathyroid
(hey take away those pitiful puppies) |
name the 10 places endocrine tissue can be found | heart, lungs, testes, ovaries, stomach, small intestine, pancreas, hypothalamus, kidneys, placenta (if pregnant) |
which endocrine glands originate from the ectoderm? | pineal, hypophysis, adrenal medulla |
which endocrine gland originates from the mesoderm? | adrenal cortex |
which endocrine glands originate from the endoderm? | thymus, thyroid, parathyroid |
name and describe the two local types of hormones | autocrines: act on themselves
paracrines: act on nearby cells |
define amine | hormone comprised of one type of amino acid |
name the amines | histamines, triptophan, tyrosine, T3 & T4 |
all amines are _____ soluble, except for __ & __, which are _____ soluble. | water, T3 & T4, lipid |
where are amines manufactured? | RER of the secreting cell |
target cell receptors are specific ________ | proteins |
define up-regulation | target cell receptors increase in number to maintain homeostasis |
define down-regulation | target cell receptors decrease in number to maintain homeostasis |
which is more common: down-regulation or up-regulation? | down-regulation |
a hormone's presence on a receptor activates the _ protein | G |
what does the activation of the G protein stimulate? | an enzyme called adenylate cyclase, which splits ATP |
as adenylate cyclase splits ___, a free _ is given off to form ___. ___ releases a free protein to become ____ | ATP, P, ADP, ADP, cAMP |
what does cAMP's presence stimulate? | protein kinases which pick up all free Ps, causing protein alteration |
define phosphorylation of protein | the process of adding free Ps to existing proteins |
what is the most common form of protein alteration? | phosphorylation |
how do lipid soluble hormones interact with target cells? | slip through the cell membrane and enter the target cell |
the lipid soluble hormone attaches to the intracellular receptor, forming a _______-________ ________ | hormone-receptor complex |
where does the hormone-receptor complex bind? | receptor proteins on the chromatin of DNA |
during transcription, the hormone-receptor complex alters the strand of ____ | mRNA |
during translation, ____ assembles a new protein from the altered ____ strand | tRNA, mRNA |
name the three ways hormones interact with other hormones | permissively, synergistically, antagonistically |
what happens when hormones interact permissively? | involves two hormones, one paves the way for the action of another
(FSH paves the way for estrogen) |
what happens when hormones interact antagonistically? | the action of one hormone opposes another
(glucagon and insulin, CT and PTH) |
what happens when hormones interact synergistically? | more than two hormones interact to achieve a common goal
most common form of interaction |
what does a feedback system do? | aids in the control of hormone secretion |
name the three components of a feedback system | receptor, brain, effector |
which is more common: positive or negative feedback? | negative |
define negative feedback | output counteracts the input |
define positive feedback | output intensifies the input |
negative feedback has a ___________-__________ effect | stimulatory-inhibitory |
positive feedback has a ___________-___________ effect | stimulatory-stimulatory |
in what three cases does positive feedback occur? | labor, clotting, disease |
name the three modes of negative feedback that control hormonal secretion | hormonal, humoral, neural |
describe the hormonal mode of negative feedback | hormones control the secretion of other hormones |
describe the humoral mode of negative feedback | blood levels of hormones control the secretion of other hormones |
describe the neural mode of negative feedback | nerve impulses control the secretion of hormones |