PSL300H1 Chapter Notes - Chapter 7: Post-Translational Modification, Tryptophan, Vasopressin
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Hormones identified by this technique of administering hormone extract to a normal animal and observing the response are sometimes called classic hormones. This includes hormones from the pa(cid:374)(cid:272)reas, th(cid:455)roid, adre(cid:374)al gla(cid:374)ds, pituitar(cid:455) gla(cid:374)ds (cid:374)ot all hor(cid:373)o(cid:374)es (cid:272)o(cid:373)e fro(cid:373) su(cid:272)h o(cid:271)(cid:448)ious gla(cid:374)ds though. Hor(cid:373)o(cid:374)e (cid:272)o(cid:373)es fro(cid:373) the greek (cid:449)ord (cid:373)ea(cid:374)i(cid:374)g to (cid:862)to e(cid:454)(cid:272)ite or arouse. (cid:863) traditio(cid:374)all(cid:455), hor(cid:373)o(cid:374)e (cid:373)ea(cid:374)t a chemical secreted by a cell or group of cells into bloodstream toward a distant target to act at low concentrations. But the definition keeps changing: hormones are(cid:374)"t o(cid:374)l(cid:455) se(cid:272)reted (cid:271)(cid:455) (cid:272)lassi(cid:272) e(cid:374)do(cid:272)ri(cid:374)e (cid:272)ells/gla(cid:374)ds. The(cid:455) are also se(cid:272)reted (cid:271)(cid:455) (cid:862)isolated e(cid:374)do(cid:272)ri(cid:374)e (cid:272)ells(cid:863) (cid:894)diffuse e(cid:374)do(cid:272)ri(cid:374)e s(cid:455)ste(cid:373)(cid:895), (cid:271)(cid:455) (cid:374)euro(cid:374)s (cid:894)(cid:374)eurohor(cid:373)o(cid:374)es(cid:895), a(cid:374)d (cid:271)(cid:455) the immune system (cytokines): hormones are not only secreted into the blood. Ectohormones are those secreted to the external environment. Pheromones are specialized ectohormones that are used to act on organisms of the same species to cause a certain behavioural or even physiological response: hormones are transported to a distant target.
