Question

Will fan and medal!
Why aren't all cells target cells? @alphadxg @TQKMB

Answer 1

well there you have it, don't you? your answer lies in the question. do you see it? =)

Answer 2

No =( I understand that target cells aren't for all hormones because their receptors only interact with certain hormones, but I think the question is asking why aren't all cells target cells with receptors for all hormones? Not sure though..

Answer 3

you're halfway there, actually. :-)

almost all hormones have specific receptors in cells. think of these receptors like translating machines. the hormone binds to the cellular receptor and thus provokes a cellular reaction.

imagine now, that every cell in your body had receptors for every possible hormone. there would be hormones binding to every single cell, always! no specificity for stuff like insuin at all, because it would be absorbed by the walls of your blood vessels before it could reach anything.

also, cells can up-regulate and down-regulate their levels of hormone receptors over longer periods. this is why caffeine works less strong, the more used to it you are.

satisfied? :-)

Answer 4

Thank you so much! I understand now! *happy dance*