Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
131 Cards in this Set
- Front
- Back
|
mediator molecules of
-nervous system |
neurotransmitters
|
|
|
neurotransmitters are released where? and in response to what?
|
locally
nerve impulses |
|
|
mediator molecules of endocrine system
|
hormones
|
|
|
hormones are carried by....
to.... |
carried by blood
to tissues throughout the body |
|
|
types of neurotransmitter target cells
|
muscle (all types)
gland cells other neurons |
|
|
types of hormone target cells
|
all body cells
|
|
|
time to onset of neurotransmitter action
|
milliseconds
|
|
|
time to onset of endocrine action
|
seconds, to hours or days
|
|
|
duration of nervous response vs. endocrine response
|
brief vs. longer
|
|
|
functions of the endocrine system
|
regulation of: extracellular fluid levels, metabolism, biological clock, contraction of cardiac/smooth muscle, glandular secretion, some immune function
growth, dvpt (fetal to adult) reproduction |
|
|
exocrine glands
secrete (...) into (....) examples: (4) |
secrete products
into ducts which empty into body cavities or body surface include: sweat, oil, mucous and digestive glands |
|
|
endocrine glands
secrete (...) into (...) examples: |
secrete products (hormones) into bloodstream
pituitary thyroid parathyroid adrenal pineal |
|
|
organs that secrete hormones as a 2nd fxn
|
hypothalamus
thymus pancreas ovaries testes kidney stomach liver small intestine skin heart placenta |
|
|
endocrine tissue can be found distributed in 3 different ways:
|
distinct, discrete organs
clusters of cells in mixed organs widely dispersed (diffuse) cells in non-endocrine organs |
|
|
types of endocrine hormones (characterized by where they go)
|
a) circulating hormones
b) local hormones paracrines and autocrines |
|
|
how many receptors can be found on one target cell?
|
2000-100,000
|
|
|
down-regulation
|
excess hormone, produces decrease in # of receptors
receptors undergo endocytosis and degradation decreases sensitivity of target cell to hormone |
|
|
up-regulation
|
deficiency of hormone, produces an increase in the number of receptors
makes target tissue more sensitive to the hormone |
|
|
RU486
|
Synthetic Hormone that blocks progesterone receptor:
(mifepristone) binds to the receptors for progesterone (necessary for implantaton and maintenace of ovum in the uterine wall) prevents progesterone binding and prevents maintenance of uterine wall for pregnancy- inducing abortion |
|
|
general mechanisms of hormone action
|
hormone binds to cell surface or receptor inside target cell
cell may then a) synthesize new molecules b) change permeability of membrane c) alter rates of reactions |
|
|
in hepatocytes, insulin stimulates
|
glycogen synthesis
|
|
|
in adipocytes, insulin stimulates
|
triglyceride synthesis
|
|
|
lipid soluble hormones
|
move through the plasma membrane and often bond to a nuclear receptor
|
|
|
water-soluble hormones
|
must link to a transmembrane receptor as a 1st messenger
and work via a second messenger system (eg G protein) |
|
|
control of hormone secretion is generally by what type of feedback?
|
negative
|
|
|
example of positive feedback control of hormone secretion
|
oxytocin on SM of uterus during labor
|
|
|
hypothalmus makes (....)
that travel via (....) directly to the (....) to induce the release of (...) |
specific releasing hormones
that travel via a closed portal system directly to the anterior pituitary to induce the release of specific pituitary hormones |
|
|
posterior pituitary is connected to what gland?
|
hypothalmus
|
|
|
the hypothalmus sends long axons to...
|
the posterior pituitary
|
|
|
the hypothalamus releases (....) or (....) into the capillary system of the (...) pituitary
|
ADH or oxytocin
released from hypothalmus into the capillary system of the posterior pituitary via long axons |
|
|
pars nervosa is also called
|
posterior pituitary, where hormones produced in the hypothalmus are released
|
|
|
pars distalis
|
anterior pituitary. stimulated by TRH (released by hypothalmus) to release TSH into circulation (which stimultaes thyroid follicular cells)
|
|
|
TRH is released by ...
|
hypothalmus
|
|
|
hypothalamus stimulated to release TRH by
|
low blood levels of T3 and T4
|
|
|
T3 and T4 are secreted by (...) following stimulation by
|
thyroid gland secretes (...) and (...) in response to stimulation by TSH
|
|
|
hormones that are made in the epithelial cells of thyroid follicles
|
T3 and T4
|
|
|
thyroid hormones are stored
|
as thyroglobulin in colloid
|
|
|
what is required for the conversion of thyroglobulin into T3 and T4?
|
iodine (trapped and oxidized, allowing for iodination of tyrosine residues of TGB)
allows coupling of: MIT (T1) + DIT (T2) = T3 DIT + DIT = T4 |
|
|
PTH is secreted in response to...
|
parathyroid secretes PTH in response to serum Ca++ levels
|
|
|
PTH activiates
|
osteoclasts to dissolve Ca++containing bone
and induces the GI tract to increase calcium absorption and the kidney to retain calcium |
|
|
Calcitonin is secreted by
|
secreted by parafollicular cells of the thyroid gland
|
|
|
PTH is made by
|
cheif cells in the parathyroid
|
|
|
oxyphil cells are found in
|
parathyroid
fxn unknown |
|
|
gland that serves as two functional endocrine organs
|
adrenal gland
medulla and cortex |
|
|
regions of adrenal cortex
|
zona glomerulus
zona fasiculata zona reticularis |
|
|
factors acting on zona glomerulus
|
angiotensin and ACTH (corticotropin)
|
|
|
hormones secreted by zona glomerulus
|
mineralocorticoids (aldosterone)
|
|
|
factors acting on zona fasiculata
|
corticotropin (ACTH)
|
|
|
hormones secreted by zona fasiculata
|
glucocorticoids (cortisol)
|
|
|
factors acting on zona reticulares
|
corticotropin (ACTH)
|
|
|
hormones secreted by zona reticularis
|
androgens
|
|
|
hormone that acts on all zones of adrenal cortex
|
corticotropin (ACTH)
|
|
|
adrenal medulla responds to what kind of stimulation
|
parasympathetic
|
|
|
adrenal medulla releases
|
epinephrine or norepinephrine
|
|
|
norepinephrine is secreted by adrenal gland when...
|
blood vessels directly supply medulla (blood lacks glucocorticoids from fasciculata)
no methytransferase enzyme induced in these chromaffin cells, therefore... |
|
|
epinephrine is secreted by adrenal gland when...
|
blood vessels in adrenal cortex pass through zona fasciculata cells in medulla
in response to ACTH glucocorticoids are released into blood, carried to medulla glucocorticoids induce methytransferase production by chromaffin cells, thus, ... epinephrine is secreted |
|
|
alpha cells secrete
|
glucagon
|
|
|
beta cells secrete
|
insulin
|
|
|
glucogon
|
makes glucose more avaiable in the blood by stimulating the breakdown of glycogen and fat through glycogenolysis and lipolysis
|
|
|
insulin
|
promotes storage of energy via glucose, particularly in liver, decreases blood glucose
|
|
|
Type I diabetes
|
autoantibodies against B cells
|
|
|
Type II diabetes
|
??
|
|
|
pineal gland is involved in (...)
responds to (...) |
diurnal cycles
light intensity |
|
|
steroids
|
-lipids derived from cholesterol
-produced on SER (by enzymes) -lipid droplets are cholesterol ester precursors??? |
|
|
hormones derived from tyrosine
|
tyroxine
and epinephrine |
|
|
thyroid hormones are bound in the blood to...
|
TBG (Thyroxine binding globulin)
|
|
|
lipid soluble proteins must attach to transport proteins in order to:
|
-improve transport by making them water soluble
-reduce hormone loss by glomerular filtration -create reserve of hormone |
|
|
free fraction
|
percent of hormone not bound to transport protein
only .1 to 10% |
|
|
water-soluble hormones
|
amine, peptide and protein hormones
and eicosanoids (fatty acid derivatives) |
|
|
serotonin, melatonin, histamine, epinephrine are all soluble in
|
water
|
|
|
eicosanoids
|
derived from achachidonic acid (fatty acid)
prostaglandins, leukotrienes, thromboxanes |
|
|
1st and second messengers are typically soluble in
|
water
|
|
|
amplification allows one molecule of epinephrine to result in
|
breakdown of millions of glycogen molcules into glucose molecules
|
|
|
cholera toxin causes
|
G protein to lock in activates state in intestinal epithelium
cAMP causes intestinal cells to actively transport chloride (Na+ and water follow) into the lumen causes massive watery diarrea |
|
|
ovulation is an example of what type of secretion pattern
|
pulsatile, regulated by LH which fluctuates with diurnal rhythms
|
|
|
binding of an agonist
|
induces events leading to a biological effect
|
|
|
antagonist
|
competes for receptor, blocking binding of an agonist
|
|
|
synergism
|
two or more hormones working together to enhance a biological effect
|
|
|
permissive effect
|
one hormone increases the activity of a second hormone
|
|
|
master endocrine glands
|
pituitary and hypothalamus
since their hormones control other endocrine glands |
|
|
hypothalamus receives input from
|
cortex, thalamus, limbic system and internal organs
|
|
|
hypothalamus controls what gland?
|
controls pituitary by secreting 9 different releasing or inhibiting hormones
|
|
|
what division of the pituitary is more cellular
|
anterior, pars distalis
|
|
|
infundibulum stalk is found in which division of pituitary?
|
pars nervosa
posterior pituitary neurohypophysis |
|
|
hormones of the posterior pituitary are produced where?
|
hypothalamus
|
|
|
what hormones travel down hypothalamo-hypophyseal tract?
|
oxytocin and ADH
travel from hypothalamus to cap. bed of posterior pituitary |
|
|
target tissue of oxytocin
|
uterus in late labor
|
|
|
pitocin
|
mimics oxytocin- induces labor
|
|
|
ADH target tissue
|
kidney, promotes water retention, causes vasoconstriction "pressor effect"p
|
|
|
pituicytes are found where?
|
posterior pituitary
|
|
|
herring bodies are found where?
|
posterior pituitary
|
|
|
herring body
|
???? dilation in neurohypophaseal tract
|
|
|
empty vesicles carried back to cell body on
|
dynein
|
|
|
hypothalamo-hypophyseal portal system
|
primary capillaries from portal system in anterior pituitary form secondary capillaries restrict activators within local circulation????
|
|
|
TSH target tissue
|
thyroid gland
|
|
|
action of TSH
|
secretion of T3 and T4
|
|
|
GH target tissue
|
most tissues
|
|
|
action of GH
|
promotes protein synthesis and growth
|
|
|
prolactin target tissue
|
mammary glands
|
|
|
action of prolactin
|
promotes growth of gland and milk secretion
|
|
|
ACTH target tissue
|
adrenal cortex
|
|
|
principal action of ACTH
|
promotes secretion of glucocorticoids and mineralocorticoids
|
|
|
FSH target tissue
|
gonads
|
|
|
FSH action
|
gamete production in both sexes, secretion of estrogen in females
|
|
|
LH target tissue
|
gonads
|
|
|
LH principle action
|
female sex hormone secretion and ovulation in females;
testosterone secretion in males |
|
|
TRH structure
|
3 AAs
|
|
|
TRH stimulates
|
thyroid stimulating hormone
|
|
|
GHRH structure
|
44 AAs
|
|
|
GHRH stimulates
|
stimulates GH secretion
|
|
|
Prolactin-Inhibiting hormone structure
|
dopamine????
|
|
|
corticotropin RH stimulates secretion of
|
adrenocorticotropic hormone
|
|
|
gonadotropin RH
|
follicle-stimulating hromone (FSH) and luteinizing hormone (LH)
|
|
|
posterior pituitary makes up approx what % of gland
|
10% of pituitary gland
|
|
|
anterior pituitary makes up approx what % of gland
|
90% of pituitary gland
|
|
|
endocrine regulated by serum calcium levels
|
parathyroid
|
|
|
parathormone
|
secreted by parathyroid in response to serum calcium levels
raises serum calcium levels by: increasing osteoclast activity increases Ca2+ resorption by kidney promotes formation of calcitrol by kidney and inhibits resorrption of phoshate (HPO4) |
|
|
calcitrol
|
produced (from vit D3) by kidney
increases Ca2+ and Mg2+ absorption by intestinal tract |
|
|
calcitonin
|
reduces serum calcium levels (produced by C cells in thyroid)
|
|
|
C cells
|
parafollicular cells of thyroid
secrete calcitonin (which reduce serum Ca2+ levels) |
|
|
iodine deficiency
|
causes a decrease in thyroid hormones (negative feedback mechanism- not "feeding back")
decrease in both thyroid and anterior pituitary activity |
|
|
cell types in parathyroid
|
chief cells (parathromone)
oxypil cells (fxn unknown) |
|
|
parathormone is made by what type of cells
|
chief cells in the parathyroid
|
|
|
zona glomerulosa
|
just inside capsule or adrenal gland
outermost zona of adrenal cortex secretes mineralcorticoids (aldosterone) in response to ACTH and angiotensin increases Na+ resorption by kidney |
|
|
zona fasciculata
|
secretes glucocorticoids (e.g. cortisol) in response to stimulation by ACTH
important in: metabolism inflammatory response supresses immune system |
|
|
zona reticularis
|
between the zona fasiculata and medulla of adrenal gland
secretes androgens (e.g. testosterone, estrogen) and small amts of cortisol in response to ACTH |
|
|
region of adrenal gland characterized by straight cords of cells
|
zona fasciculata (intermediate zona of cortex)
stimulated by ACTH secretes glucocorticoids |
|
|
zone glomerulosa
|
characterized by rounded clusters of cells
secrete mineralcorticoids (aldosterone) |
|
|
epinephrine is secreted by...
|
-chromaffin cells of adrenal medulla
-that have been supplied by sinusoidal vessels ( travel zona fasiculata of adrenal cortex- where glucocorticoids are secreted) glucocorticoids induce the production of methyltransferase (an enzyme that adds the extra methyl group to |
|
|
norepinephrine is secreted by...
|
chromaffin cells of the renal medulla
supplied by medullary arterioles (go directly to medulla) do not carry glucocorticoids, no methyltransferase induced, no extra methyl group |
|
|
colchine
|
used in creating chromosome spread
added to culture to to block microtubules, stopping the chromosomes at the end of prophase, before their movement into metaphase. |
