Exam 10: March 27-31 Flashcards
does hypothyroidism have negative feedback?
no negative feedback
what are symptoms of hypothyroidism?
- increased TSH
- over-stimulated follicular cells
- enlarged gland = goiter
what is another name for hyperthyroidism?
Grave’s disease
what is hyperthryoidism caused by?
it’s an autoimmune disease
when the immune system causes problems, it’s called a self immune
caused by an antibody
proteins that are normally there to identify our pathogen’s antibodies are instead binding to TSH receptors and causes our TSH to act as if it’s there and get T3 and T4 to be made
does hyperthyroidism have negative feedback?
no
there’s negative feedback if TSH and TRH are there but neither of them is what’s causing the increase in T3/T4; it’s the antibody that’s boning to the receptor and acting as an agonist
can T3/T4 do negative feedback?
no they can’t do negative feedback on the immune system
what is happening physiologically if you have hyperthyroidism?
very high levels of T3 and T4 because the antibody is causing it to be produced, not the pathway
TSH and TRH levels are dropped - they aren’t what’s causing the high levels of T3/T4 since TSH receptors in the follicular cells are being activated by the antibody
do people with hyperthyroidism get goiters?
very because the antibody is overstimulating the follicular cells so you end of with a goiter
what are symptoms of hyperthyroidism?
1) heat intolerance: individuals have very high metabolism so they’re producing lots of heat – compared to hypothyroidism that gets very cold
2) decreased weight: due to burning glucose and high metabolism
3) increased sympathetic response: helped by T3 and T4 so you get jumpy
where is the adrenal gland located?
it sits on top of the kidney
what’s the composition of the adrenal gland?
1) cerebral cortex
2) medulla: sympathetic ganglion
what endocrines are secreted by the adrenal gland?
corticosteroids (steroids)
what impacts do the endocrines of the adrenal gland have?
metabolic saving processes
it tries to keep us from starving
what does cortisol do? where is it secreted from?
it’s secreted by the adrenal gland
1) stress endocrine
2) acts on the liver
3) increases breakdown of fat components
4) acts on epinephrine and norepinephrine
5) anti-inflamatory
how does cortisol act as a stress endocrine?
having enough energy and food was a big problem and the job of adrenal gland endocrines is to impact the metabolic saving processes to keep us from starving
cortisol comes into play to make sure that we can shut down the things we don’t need as much to make sure we have enough glucose for later
makes sure we’re alive tomorrow
how does cortisol act on the liver?
cortisol mainly acts not he liver
it increases catabolism (breakdown) of glucose so that we can do our equation 2 to get energy available
how does cortisol increase breakdown of fat components?
this is why stress sometimes costs weight loss since fat storage are being broken down
then cortisol starts breaking down proteins which means muscle loss
then after it will eventually break down bone because we don’t need any of those stores if we aren’t going to be alive tomorrow
how does cortisol act on epinephrine and norepinephrine?
it acts on epinephrine and norephinephrine to impact blood pressure
they are sympathetic NTs which makes sense because we’re stressed out
sympathetic system gives you high blood pressure so you can move nutrients out to the muscles where they’re needed
how does cortisol act as an anti-inflammatory?
inflammation is our immune system
so cortisol works against immune system to reduce it because we’re trying to save energy and one of the ways to accomplish that is to lower things that we don’t need
what are the costs of cortisol?
1) cortisol decreases growth
if you don’t have enough energy to make small you function, why would you want to get bigger if you can’t support it?
2) cortisol reduces reproduction
don’t take girls to scary movies because they induce stress which means high cortisol which means reduced reproductive interest
do humans need cortisol?
yes
when there’s no cortisol, you’re dead within days
when you drop below a certain cortisol threshold, you’re in extreme danger; you need some cortisol going through the system
what are the two types of adrenal gland disorders?
1) adrenal insufficiency
2) hypercortisolism
what is adrenal insufficiency disorder? what’s another name for it?
it’s a type of hypothyroidism because you have low cortisol levels but cortisol is still there; you’re just not producing enough to be in the safe range
“Addison’s syndrome”
what are symptoms of adrenal insufficiency disorder?
individual will be weak – you need cortisol to impact liver to get glucose put into the system so without cortisol the glucose levels drop too low and you can’t run equation 2 as efficiently
without enough cortisol you’ll have low BP because of low epinephrine and norepinephrine levels
