Homeostasis

Homeostasis

1. + Positive Feedback

   • Enhance stimulus
   • E.g. Child birth & blood clotting

2. - Negative Feedback

   • Reverse stimulus
   • E.g. Maintaining body temp & blood glucose levels

3. Stimulus

   • Receptor
     • Control centre
       • Effector
         • Physiological response
           • Evaporation of sweat, body temp falls, stimulus ends
         • Responds to change
           • E.g. Sweat glands activated
       • Efferent pathway
         • Info sent from control centre to effector
       • Measures change against set point
         • E.g. Thermoregulatory centre in brain
     • Afferent pathway
       • Info sent from receptor to control centre
     • Detects change
     • E.g. Temp-sensitive cells in skin & brain
   • Produces change
   • E.g. Body temp rises

4. Maintain balance

   • Optimal functioning
     • Internal environment