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
what is hypercortisolism? what’s another name for it?
too much cortisol in the system
this doesn’t mean the person is under stress all the time – this is someone who is Hawaii relaxing on a beach yet their cortisol levels are still high; it’s an unnatural response
“Cushing’s syndrome”
what are physiological symptoms of hypercortisolism?
1) individuals will have high glucose levels because liver is being impacted by cortisol
high glucose levels people usually get diagnosed as being diabetic when they actually just have hypercortisolism
2) individuals usually have high BP
3) shut down of immune system so immune response is lowered/suppressed by cortisol
4) fragile bones because you’re breaking down fats, proteins then bone
5) distinct obesity pattern
what obesity pattern is associated with hypercortisolism?
you might say this doesn’t make sense since they’re putting so much energy in the system they should be losing weight…
but if you put high levels of cortisol in and keeping it in the system
cortisol wants to make sure you don’t starve so if you have all this extra energy in the system, the cortisol requires what isn’t used and putting it back into fat resources you can use later just incase you don’t get to eat tomorrow
the fat gets repositioned around organs so you see lots of belly fat and around your neck because you have vital organs in your belly and your brain in your head
what is somatic growth?
involves adding cells to you via mitosis
NOT adding reproductive cells via meiosis
what is needed for somatic growth?
1) increase protein synthesis
2) increase glucose catabolism
3) increase adipose catabolism
4) increase bone growth at epiphyseal plates
how does protein synthesis impact somatic growth ?
you have to increase potion synthesis
making proteins costs us energy
why is glucose needed for somatic growth?
need to increase glucose catabolism
running our equation 2 to get ATP which are needed for protein synthesis process
why is fat needed for somatic growth?
you need to increase adipose catabolism
need to break into fat storage
where do bones growth?
bones only grow at the epiphyseal plates near the ends of the bone
you don’t grow from the middle of your bone
you don’t see adults get taller, they just get more massive, because the plates gets fused
the steroids associated with puberty is what causes the plates to fuse which stopes upwards growth by changing bones and not allowing them to increase in length
this dow not mean growth is stopping because you can grow towards in weight gain
why does somatic growth need increased bone growth at the epiphyseal plates?
you can add all these cells being made to the bones at the epiphyseal plates
if you damage one of the plates in a kid, you need to get it checked out because you could have damaged the plate and they could end up with growth deficits
what endocrines controls somatic growth?
1) growth hormone
2) T3/T4
3) insulin
4) sex endocrines
5) cortisol
when are GH levels highest? specifically during a life time and throughout the day
highest during development
not consistently high though because you have growth spurts
it’s an endocrine that’s most active at night, not during the day which makes sense because GH needs a lot of energy and at night you can devote all your energy to it