CM Endo Flashcards
what is the purpose of the endocrine system?
speed?
uses hormones released from glands into the blood and transports them throughout the body to influence the activity in other tissues
slow speed
longer results
(takes longer than neurotransmitters but sticks around for longer)
what are 7 endocrine glands in the body?
pituitary
thyroid
parathyroid
adrenal glands
pancreas
gonads
hypothalamus
endocrine hormones
what are they?
released into the bloodstream, this is most common, circulates to distant targets,
paracrine hormones
what are these?
hormone acts locally on other cells other than the ones that produce it
ex: sex steroids on the ovary
autocrine hormones
what are these?
acts on the tissue it comes from
ex: release on insulin from pancreatic beta cells since the release inhibits these same cells
hormones
4 properties
- blood borne signals released by endocrine glands
- may be transported free or bound to carrier protein
- different cells can respond differently to the same hormone
- cells can have the same response to different hormones
what are the transportation mechanisms for hormones?
free
bound
free or unbound molecules
what is this?
peptide hormones and protein hormones are water soluble so therefore don’t need a carrier

free=water soluble
hormones bound to carriers
what are these? (2)
what do they come from?
length of activity?
steroid hormones and thyroid hormones are carried by specific carrier proteins synthesized in the liver and cross membrane because lipid soluble

***the more binding that is present, the longer it stays in the system**
bound hormone=lipid soluble
what are 3 ways hormones are degredated?
1
1
3
- may be destroyed by enzymes at the receptor site (epi)
- may be taking up by cells and destroyed (peptide hormones)
- may be destroyed in the liver and excreted in the bile (steroid hormones, T3, T4)
protein and peptide/polypeptide hormones
solbulity?
size?
how eliminated?
length of life?
receptor binding mechanism?
4 example hormones?
- water soluble and circulate freely in the blood
- small to large
- degraded by enzymes in the blood or tissue and excreted by kidneys and liver
- short lifespan in circulation
- bind with RECEPTORS on the surface and use secondary messangers
Ex:
- insulin
- glucagon
- hypothalmus hormones
- pituitary hormones

steroid hormones
what does it come from?
membrane permeability?
receptor location?
type of messenge?
ultimate effect?
5 hormones
- come from cholesterol
- can pass through lipid membrane
- interacts with intracellular receptors in cytoplasm or on nucleus
- primary messenger since enters cell
- effect is transcription and translation of new gene
ex:
- estradiol
- testosterone
- aldosterone
- cortisol
- glucocorticoids

amines/amino acids
made from?
behave like?
2 hormone examples? made from?
- derived from tyrosine
- behave like proteins and peptides
ex:
- NE and EPI
- made from 1 single amino acid tyrosine - thyroid hormones
- makde from 2 tyrosines

T3/T4 and NE/EPI, although being amines, behave like? what does this mean?
BEHAVE LIKE PROTEINS AND PEPTIDES
- water soluble
- bind with receptor on surface and use secondary messangers

what is the range in size for the polypeptides/proteins?
3-200 amino acids
explain how proteins and polypeptides are synthesized?
4
vessicle mediated
- synthesizied in the rough endoplasmic reticulum into precursor hormone called “prohormone”
- moves to golgi appartus** and **packaged into vessicles
- prohormones are converted to hormones once in the vessicle, if present
- once endocrine cell is stimulated** the **vessicles go to the surface to release hormone
what is the most prominent class of hormones?
proteins and poly peptides
explain the synthesis of steroid hormones?
what to keep in mind about this process?!
nonvessicle mediated
- synthesized in the smooth endoplasmic reticulum (hence why steroid producing tissues have a large amouth of SER)
- some steroids serve as precursors for production of other hormones
- *****process not completely understood****
what type of receptors do polar, water soluble hormones bind to?
what two types of hormones use this methode?
example hormones within that class?
3
4
bind to plasma membrane receptors on outside of cell

1. proteins and peptides/polypeptides
-hypothalmus and pituitary hormones
-glucagon
-insulin
2. amines
(epi, NE, dopamine, T3, T4)
what type of receptors do non-polar, lipid soluble molecules bind to?
class that uses this method?
4 hormones that use this?
pass through membrane and bind to intracellular receptor

example:
steroids
- aldosterone
- cortisol
- estradiol
- testosterone
amino acid hormones (proteins + peptides/polypeptides)
what is there ultimate effect?
speed?
duration of effect?
use cell membrane receptors to alter existing proteins in target cells
fast-acting
shor duration of effects
steroid hormones
what is their ultimate effect?
speed of effect?
duration of effect?
use intracellular receptors to synthesize new proteins
slow acting
long lasting effects
hormone receptors
where are they?
what do they do?
response is dependent on? 2
can they number increase or decrease?
- located intracellularly or on membrane
- recognize a specific hormone and translate it into cellular response
3. response varies with number of receptors present and affinity
- the number of receptors changes for number of reasons
upregulation of hormone receptors
what are two ways this can occur?
- decreased hormone levels increases the number of receptors so the cell is more sensitive to the decreased levels of hormone, negative feedback
- sometimes the receptors can increase in response to increase hormone, causing a positive feedback
























































































