Endocrine system“Hormones will rock your world”
WHAT IS IT? Group of organs and tissuesthat control and regulate themetabolic functions of thebody by using chemicalsubstances calledhormones.
HORMONES• Chemical substancesproduced byspecialized cells.• They act as chemicalmessengers.• Direct release into theblood stream:• Alone• Associeated• 2 types of action:• Autocrine• ParacrineGLANDULES• Organs or tissues thatsecrete hormones.• Secrete substancesfor an action on adistant target or overthemselves.
CHARACTERISTICSAct over the heart.Release in extracellular space.Diffuse into blood vessels and travel throught the blood stream.Affect tissues that can far away from the point of origin of the hormone.Its effect is directly proportional to its concentration.Regulate how the body works.Independently of the concentration, its function is related to the correctresponse of the receptor.
EFFECTSStimulant:Promotes activity in a tissue (eg, prolactine).Inhibitant:Decreases activity in a tissue(eg, somatostatine).Antagonist:When a couple of hormoneshave opposite effects(eg, insuline & glucagon)Sinergist:When a couple of hormonesproduce a more powerfulreaction than when they areseparated (eg HGH & T3/T4)Tropic:This hormone affects the tissueof an specificglandule, (eg, gonadotropine works as chemical messenger).