Endocrine System
hormone that influences the adrenal cortex
ACTH
hypothalamic hormone important in regulating water balance
ADH
The __ is called the master endocrine gland because it regulates so many other endocrine organs
Anterior pituitary
hormone that influences testes & ovaries
FSH and LH
anterior pituitary hormones that regulate the ovarian cycle
FSH, LH
hormones that act directly or indirectly to elevate blood glucose include
GH, cortisol, CRH
tropic hormones secreted by the anterior pituitary gland include
LH, ACTH, TSH, FSH
The secretion of most hormones is regulated by ____ system, in which increasing levels of that particular hormone turn off its stimulus
Negative feedback
most important hormone regulating the amount of calcium circulating in the blood; released when blood calcium levels drop
PTH
hormone that influences thyroid
TSH
regulate the function of another endocrine organ; tropic hormones
TSH, ACTH, FSH, LH
organ that produces or releases aldosterone
adrenal gland (cortex)
organ that produces or releases cortisone
adrenal gland (cortex)
organ that produces or releases epinephrine
adrenal gland (medulla)
G Protein molecule acts as a intermediary to activate the enzyme ___, which catalyzes the conversion of intracellular ___ to cyclic AMP
adynelate cyclase, ATP
The extent of target cell activation by hormone receptor binding depends equally on these three factors
affinity of the receptor for the hormone; relative number of hormone receptors on the target cells; hormone blood levels
adrenal cortex hormone involved in regulating salt levels of body fluids
aldosterone
Hormones promote homeostasis by ____ of body cells rather than by ____.
altering activity, stimulating new or unusual activities
excessive amounts of ___ results in abnormal hairiness, masculinization
androgens
a hormone opposes or prevents the action of another hormone on a target cell
antagonism
Organ that produces or releases ACTH
anterior pituitary
organ that produces or releases FSH
anterior pituitary
organ that produces or releases LH
anterior pituitary
organ that produces or releases MSH
anterior pituitary
organ that produces or releases TSH
anterior pituitary
organ that produces or releases growth hormone
anterior pituitary
organ that produces or releases prolactin
anterior pituitary
inadequate amounts of __ results in polyuria without high blood glucose levels; causes dehydration & tremendous thirst
antidiuretic hormone (ADH)
decreases blood calcium
calcitonin
The ion ___ can act intracellularly as a "third messenger" in certain cases.
calcium
four ways hormones may alter cellular activity
change in membrane permeability and/or voltage; enzyme activation/inactivation; initiation of secretory activity; synthesis of regulatory molecules such as enzymes
increases blood glucose
cortisol, GH, glucagon, epinephrine
increases blood pressure
cortisol, aldosterone, thyroxine, epinephrine
Hormone that helps protect the body during long-term stressful situations, such as extended illness & surgery
cortisone
In addition to Cyclic AMP, many other molecules are known to act as second messengers which include
diacylgylcerol, inositol triphosphate, cyclic GMP
The mechanism by which most steroid-based hormones influence their target cells
direct gene activation
reduced target cell response to continued high hormone levels in the blood
down-regulation
Short-term stress hormone; aids in the fight-or-flight response; increases blood pressure & heart rate
epinephrine
directly regulate the menstrual or uterine cycle
estrogen, progesterone
inadequate amounts of __ results in spontaneous abortion
estrogen/progesterone
Inadequate amounts of _____ results in maturation failure of reproductive organs
estrogen/testosterone
hormones secreted by females include
estrogens, progesterone, prolactin, testosterone
In the cyclic AMP mechanism, the hormone, acting as the ____ messenger, bind to target cell membrane receptors coupled to a signal transducer called ___
first, G protein
acts antagonistically to insulin; produced by the same endocrine organ
glucagon
excessive amounts of __ results in cushing's syndrome; moon face, hypertension, edema
glucocorticoids
Hormone that influences bones and muscles
growth hormone (GH)
excessive amounts of _ results in abnormally large stature, relatively normal body proportions
growth hormone (GH)
excessive amounts of __ results in acromegaly in adults
growth hormone (GH)
inadequate amounts of __ results in abnormally small stature, normal proportions, a "tom thumb"
growth hormone (GH)
period of persistence of a hormone in the bloodstream
half-life
Major stimulus for release of adrenocorticotropic hormone
hormonal
major stimulus for release of estrogen & progesterone
hormonal
major stimulus for release of insulin
hormonal
major stimulus for release of thyroxine & triiodothyronine
hormonal
major stimulus for release of calcitonin
humoral
major stimulus for release of parathyroid hormone
humoral
organ that produces or releases ADH
hypothalamus
organ that produces or releases oxytocin
hypothalamus
the pituitary gland hangs from the floor of this neuroendocrine gland
hypothalamus
inadequate amounts of __ results in excessive thirst, high blood glucose levels, acidosis
insulin
necessary if glucose is to be taken up by most body cells
insulin
decreases blood glucose
insulin, thyroxine
major stimulus for release of epinephrine
neural
major stimulus for release of oxytocin & antidiuretic hormone
neural
The hypothalamus is part of the brain and is called ____ organ.
neuroendocrine
organ that produces or releases progesterone
ovaries, placenta (adrenal cortex)
organ that produces or releases estrogens
ovaries, placenta, (adrenal cortex)
Hormones released by neurons
oxytocin, ADH
necessary for milk production and ejection
oxytocin, prolactin
organ that produces or releases glucagon
pancreas
organ that produces or releases insulin
pancreas
increases blood calcium
parathormone
Small glands that ride "horseback" on the thyroid
parathyroid
excessive amounts of __ results in demineralization of bones; spontaneous fractures
parathyroid hormone (PTH)
inadequate amounts of __ results in tetany
parathyroid hormone (PTH)
organ that produces or releases PTH
parathyroids
another hormone must be present for a given hormone to exert its effects is
permissiveness
Associated with a second messenger system
phosphatidyl inositol, glucagon, calmodulin
organ that produces or releases melatonin
pineal
Endocrine producing organ present only in pregnant women
placenta
hormone that influences mammary glands
prolactin (PRL)
Subsequent events of the second messenger system are mediated by the activation of enzymes called ___ which in turn activate or inactivate other enzymes by adding a ___ group to them
protein kinases, phosphate
Only cells that have proper ___ on their cell membranes are activated by the chemical messengers
receptors
The anterior pituitary is controlled by ___ secreted by the ____.
releasing & inhibiting factors, hypothalamus
Cyclic AMP acts as the ___ messenger to initiate a cascade of reactions in the target cell.
second
Most hormones are ____ molecules
steroid or amino acid-based
combined effects of several different hormones acting on a target cell are amplified
synergism
The sequence of events initiated by the second messenger depends on __,___,&___
target cell type kinases contained in the target cells substrates available for phosphorylation
Responsive cells are called ___ of the various endocrine glands
target cell(s)
organ that produces or releases testosterone
testes (adrenal cortex)
hormone that "programs" T lymphoctyes
thymosin
organ that produces or releases thymosin
thymus
organ that produces or releases calcitonin
thyroid
organ that produces or releases thyroxine
thyroid
Basal metabolic hormone
thyroxine
excessive amounts of __ results in bulging eyeballs, nervousness, increased pulse rate, weight loss (grave's disease)
thyroxine
inadequate amounts of __ results in a goiter
thyroxine
inadequate amounts of __ results in cretinism
thyroxine
inadequate amounts of __ results in myxedemia in the adult
thyroxine
target cells respond to continued high hormone levels by forming more receptors capable of binding the hormone
up-regulation
