Endocrine Flashcards
a ____ is a chemical substance secreted by a group of cells into body fluids (blood) that has a physiological effect on other cells that express the receptor
hormone
hormones are potent in small concentrations due to ____
amplification
what is it called when hormones work with other hormones to elicit a cellular response?
hormone-hormone interaction
what type of hormone-hormone interaction is when one hormone initiates a small response on it’s own, but exposure to another hormone causes a greater response
permissive hormones
what type of hormone-hormone interaction is this: epinephrine weakly stimulates lipolysis, but in the presence of T3 and T4, lipolysis is strongly stimulated
permissive hormones
this hormone-hormone interactions works by increasing the number of receptors on the target cell which results in a larger response
permissive hormones
what type of hormone-hormone interaction is where one hormone has a small effect and a second hormone has a small effect but when released together, their effects are greater than the sum of the individual hormones
synergistic
what type of hormone-hormone interaction is this: glucogon and epinephrine work to increase blood glucose on their own, but together they can rise glucose even more than the sum of the two individual hormones
synergistic
this hormone-hormone interactions works by amplification of a second messenger system
synergistic
what type of hormone-hormone interaction is where one hormone opposed the actions of another hormone
antagonistic
what type of hormone-hormone interaction is this: insulin and glucogon have opposing effects
antagonistic
what are the 2 types of hormones?
steroid and protein
steroid hormones are ____ derivative
cholesterol
steroid hormones ____ through membranes
dissolve
what type of hormone is slow acting and long lasting?
steroid
what hormone type has a long half life of hours to days?
steroid
how are steroid proteins transported?
in the blood by a protein
protein carriers shield the steroid hormone from ___
degradation
hormones must ____ from the carrier to bind to the receptor
unbind
where are the receptors for steroid hormones located?
intracellular
what is the mechanism of action for steroid hormones?
initiate cellular transcription
what is the name of the enzyme that coverts testosterone to estradiol?
aromatase
___ hormones dissolve in the plasma so no carrier is required
protein
what type of protein is fast acting and short lasting?
protein
protein hormones have a ___ half life
short
how are protein hormones transported?
carried dissolved in the blood
protein hormones are susceptible to ___ ____ by enzymes found in the blood
rapid degeneration
where are the receptors located for protein hormones?
plasma membrane
what is the mechanism of action for protein hormones?
binds plasma membrane receptors to second messenger system
what are the 2 reasons a second messenger system is used?
activation at each step activates larger number of protein, amplification allows a small amount of protein hormones to have a large cellular effect
is there new protein synthesis in the mechanisms of protein hormones?
no, they are already made and sitting in the cytoplasm
what activates the cascade in the protein hormone pathway/second messenger response?
the binding of the hormone to it’s receptor
___ kinase can phosphorylate ____ proteins in seconds, quickly amplifying a signal
one, many
hormones travel in the blood until the reach a ___ ____
capillary bed
what is an endocrine cell?
any cell that puts hormones into the blood
____ is the ability of a target cell to respond to a hormone
sensitivity
sensitivity is a reflection of what?
number of receptors
___ regulation decreases receptor expression and decreases sensitivity
down
_____ regulation increases receptor expression and increases sensitivity
up
chronic stress and GH receptor is an example of ___ regulation
down
exercise and insulin receptors is an example of ___ regulation
up
the ___ ___ is an extension of the hypothalamus
posterior pituitary
the hormones released from the ___ pituitary are released directly into the bloodstream
posterior
the hypothalamus and anterior pituitary are connected by the ___ ___ _____
hypothalamic portal system
the anterior pituitary has a set of hormone secreting cells that are sensitive to what?
hormones secreted from the hypothalamus
in response to hypothalamic hormones, the anterior pituitary releases what?
hormones into the bloodstream
does the posterior pituitary synthesize hormones?
no
neurosecretory cells of the hypothalamus can produce what two hormones?
oxytocin, ADH
what pituitary is a two tiered system?
posterior
what pituitary is a three tiered system?
anterior
what category of hormones are released from the hypothalamus (tier 1)?
releasing
what category of hormones are released from the anterior pituitary (tier 2)?
stimulating
how do hypothalamic hormones reach the anterior pituitary?
portal system
what is tier 3 of the anterior pituitary?
delivery of hormones to the target endocrine gland
increase in peripheral hormones inhibits release of what?
both releasing hormone and stimulating hormone
increasing stimulating hormone does what to releasing hormone?
inhibits release
___ hormones are stimulating hormones that target other glands and result in the release of a second/peripheral hormone
tropic
___ hormones are secreted from the pituitary and do not elicit secretion of a new hormone
direct
what are the 3 hormones released in the negative feedback of cortisol?
CRH, ACTH, cortisol
where is CRH released from in the stress response?
hypothalamus
where is ACTH released from in the stress response?
anterior pituitary
where is cortisol released from in the stress hormone?
adrenal gland
what are the 3 roles of cortisol in the body?
stimulate gluconeogenesis, raise blood pressure, anti-inflammatory
is ACTH tropic or direct?
tropic
what are the 3 hormones released in the negative feedback regulation of thyroid hormone?
TRH, TSH, T3/T4
where is TRH released from in regulation of thyroid horomone?
hypothalamus
where is TSH released from in regulation of thyroid hormone?
anterior pituitary
where are T3/T4 released from in regulation of thyroid hormone?
thyroid
what are the 4 functions of T3/T4 in the body?
regulate BMR, enhance epinephrine, regulate growth of nervous tissue, aid in overall growth
if tier 1 is activated, what always happens to tier 2?
becomes activated
if tier 2 is activated, what always happens to tier 3?
becomes activated
what two hormones are involved in the negative feedback of growth hormone?
GHRH, GH
what is the direct hormone result of GH?
metabolic switch
what is the trophic hormone result of GH?
liver causing release of IGF-1
what will hypoglycemia, decreased plasma fatty acids, and deep sleep do to the growth hormone pathway?
turn it on
what will hyperglycemia, increased plasma fatty acids, decreased blood levels of amino acids, and high blood levels of GH and IGFs do to the growth hormone pathway?
turn it off
what occurs during metabolic switch?
body stops using glucose as main source of energy and starts using fats
____ hormone promotes growth and development of bones, neurons, and other tissues
IGF-1
what happens to the growth plate/epiphyseal plate after puberty?
seals and calcifies to reach adult height
how are proteins turned on in the second messenger response?
phosphorylated
