Endocrine Flashcards
many hormones are synthesized in
several tissues
for most hormones, a tissues produces the hormone in _____(the gland) and other tissues secrete the hormone in ____ quantities
the gland produces large amounts of the hormone and other tissues secrete much smaller amounts of the hormone.
hormones are released in response to
an alteration in the cellular environment
hormones are released to maintain
a regulated level of certain substances or other hormones
what are hormones regulated by?
chemical, hormonal, or neural factors.
what are some water soluble hormones?
peptides
catecholamines
how do water soluble hormones circulate in the blood stream?
they generally circulate as free hormones
what are some water insoluble hormones?
steroid hormones
thyroid hormones
how do water insoluble hormones circulate in the blood stream?
they are carried in the blood bound to plasma proteins.
At low concentrations they are dissolved in the blood and travel as free hormones
water insoluble hormones reach an ____ between the protein bound hormone and the free hormone
equilibrium
the protein bound hormone cannot _____ and therefore serves as a circulating ___
cannot bind to receptors and therefore serves as a circulating reservoir for the hormones
which hormone is the active hormone? the free or the bound?
the free hormone is the active hormone
what affects the ratio of free to bound hormones?
changing the concentration of hormone binding proteins in the plasma.
drugs that compete for binding sites
what can change the concentration of hormone binding proteins in the plasma?
liver damamge
malnutrition
hormones such as estrogen
autocrine interactions
a cell releases hormones that affect itself and all identical cells
paracrine interaction
a cell releases hormones that affect cells around it in the same tissue
classic endocrine interactions
cells in one tissue produce hormones that affect cells in another tissue
what are the action of water soluble hormones?
signal transduction
second messenger
first messenger
what are examples of first messenger water sol hormones?
peptide hormones
what are examples of second messenger water sol hormones?
calcium
cAMP
what are possible causes of altered hormone levels?
usually a problem of the production or the reception of the hormone
failure of feedback systems
what alters hormone production?
dysfunction of an endocrine gland
ectopic hormone release
increased hormone degradation or inactivation
what might cause dysfunction of an endocrine gland?
secretory cells are unable to produce, obtain or convert hormone precursors or
the endocrine gland synthesizes or releases excessive amounts of hormone
how might there be altered hormone reception?
receptors associated disorders
inadequate synthesis of a second messenger