Receptors > identifies change to normal functioning occuring, and responds to change and monitors it. Change is named stimuli. It response by sending information along the affernt pathway to the control centre (brain).
Control centre > information is received, analysed, and identifies action that needs to be taken. Messenge is then send along efferent pathway to the effector.
Effector > site of reponse to stimuli. It either reduce the stimuli (-ve feedback) or increases it (+ve feedback).