Endocrine system Flashcards
what two systems work together to coordinate the function of all body systems?
nervous and endocrine systems
how would you describe the time for the endocrine system to take action?
seconds to hours / longer then nervous system
is the endocrine a slower response or faster?
slower
how do mediator molecules of the endocrine system travel or communicate?
via bloodstream
what are the target cells of the endocrine system?
all cell types
what is the definition of a hormone?
a mediator molecule that is released in one part of the Body but regulates the activity of other part of the body
what are the exocrine glands responsible for?
products are created and secreted into the ducts that carry the secretion to then body structures
(leaving the body via ducts)
what are the endocrine glands?
products are secreted into the interstitial fluid surrounding the secretory cell receptors rather then ducts
(no ducts)
what things are considered endocrine glands?
pituitary
thyroid
parathyroid
adrenal gland
pineal gland
where is the thymus located?
above the heart
how do hormones influence cells?
chemical binding to protein receptor
what is down regulation?
makes a target cell less sensitive to hormones when targeting cell receptors are decrease
what is up regulation?
miles target cells more sensitive when an increase of hormone is present
what are most endocrine hormones considered?
circulating
what inactivates the circulating hormones?
liver
what excretes circulating hormones?
kidneys
what happens to someone with kidney failure with circulating hormones?
excessive hormone build up in the blood
what are local hormones?
act on neighbouring cells or the same cell
describe the paracrine hormones
local hormones that act on neighbouring cells
describe autocrine hormones
local hormones that act on cells that they’ve secreted from
what are the three classes of lipid hormones?
steroid
thyroid
gas
what are the three classes of water-soluble hormones?
amines
peptides and proteins
eicosanoids
what are the three functions of transport proteins?
males lipid soluble hormones temporarily soluble in water
slow passage of small hormones into the kidneys
provides ready reverse hormones
what percent of are not bounded to transport proteins?
0.1-10%
what are the none bounded proteins to transport proteins called?
free fractions
what happens with loss of free fractions?
they become replicated into new hormones to replenish the loss free fraction
what things are considered normal to response of hormones?
synthesis
changing of plasma membrane
stimulating transport
alters metabolic rate
contraction of smooth muscles or cardiac
what must happen for a lipid-soluble hormone to bind?
must bonded inside the target cell before any response can occur
what must happen for a water soluble hormone to bind
binding to the plasma membrane of target cell
what hormones binds to receptors within the target cell?
lipid soluble
what is the mechanism of action of lipid soluble hormones?
diffuse across the plasma membrane and target those receptor cells found within the cytoplasm
what os the mechanism of water-soluble hormones?
they cannot diffuse into the target cell
they bind to the receptors that protrude from the surface
what is the first message?
involves water soluble hormones
cause the production of a second message inside the cell
what things are considered second messengers?
neurotransmitters
neuropeptides
transduction
what are G proteins?
a type of the first message that helps activate second message. A very common future of secondary messages
whoa does the secondary messanger work?
they translate the outer message and function within the cel
what are the permissive effects?
stimultaneous or recent exposure to a secondary hormone
what is the synergistic effects?
when the effect of two hormones acting together is greater than or more extensive then one acting alone
what is the antagonistic effect?
the one hormone opposes the action of another
what things regulate hormone secretion?
signals from NS
chemical changes of blood’
other hormones
what is more common to hormones
negative or positive feedback?
negative
what is the master gland?
pituitary gland
what is the master of the endocrine system?
hypothalamus
where is your hypothalamus located?
a small region of the Brian below the thalamus
what joins the hypothalamus and the pituitary gland together?
infundibulum
what are the cells of the hypothalamus responsible for?
synthesizing 9 different hormones
what are the cells of the pituitary gland responsible for?
secreting 7 different hormones
what percentage of the pituitary gland does the anterior lobe make up?
75%
what kind of tissue makes up the anterior lobe?
epithelial tissue
how does the anterior lobe transport hormones?
via blood stream
what kind of tissue makes up the posterior lobe?
neural tissue
what is the function of the posterior lobe?
stores and releases 2 hormones
what two hormones are related by the posterior lobe?
ADH
oxytoicin
what two parts make up the anterior lobe?
pars distils
pars tubercles
what two things make up the posterior lobe?
pars nervose
infundibulum
what is the third region of the pituitary gland called?
pars intermedia
what is the system of the anterior pituitary system called?
hypophyseal portal system
how does blood get carried into the anterior lobe?
capillary - portal vein - capillary
one capillary leads to the veins
other to the heart
what are the special neurons called?
neurosecretory cells
what five cells are present in the anterior pituitary gland?
somatotrophs
thyrotrophs
gonadotrophs
lactotrophs
corticotrophins
match the following cell to the hormone released:
- somatotrophs ACTH / adrenocorticotrphic
- thyotrophs PRL / prolation
- gonadotrophs LH / FSH
-lactotrophs TSH / thyroid stimulating
- corticotrophins. GH / growth hormone
somatotrophs = GH
thyrotrophs = TSH
gonadotrophs = FSH / LH
lactotrophs = PRL
corticotrophins = ACTH
how are the 7 hormones secreted in the hypothalamus?
neurosecretory cells
- 5 releasing 2 inhibiting
negative feedback
what is growth hormone responsible for?
growth of the body cells, protein synthesis, tissue repair, lipolysis and elevation of blood glucose concentration
what tissue does growth hormone target ?
liver
bones and skeletal tissue
what is thyroid stimulating hormone for?
stimulates synthesis and secretion of thyroid hormones
what is follicle stimulating hormone for?
females: initiates development of oocytes and induces ovarian secretion of estrogen
men: stimulates testes to produce sperm
what is luteinizing hormone for?
females: stimulates secretion of estrogen and progesterone and ovulation or formation of corpus lutenum
men: stimulates testes to produce testosterone
what is prolactin for?
promotes milk production
what is ACTH for?
stimulates secretion of glucocorticoids
what is MSH for?
darkening of skin
is hypoglycaemia or hyperglycaemia more dangerous?
hypoglycaemia