B6: Brain and Mind

B6: Brain and Mind

1. Responding to Environmental Changes

   • Responding to a Stimulus
     • STIMULUS: a change in the environment of an organism
     • animals respond to stimuli in order to keep themselves in favourable conditions, eg...
       • moving to somewhere warmer if they're too cold
       • moving towards food if they're hungry
       • moving away from danger to protect themselves
     • not responding to a stimulus is a super effective way to die - at the end of the day stimuli are there to keep organisms alive
   • Receptors
     • RECEPTOR: an organ or cell able to detect an external stimulus and transmit a signal to a sensory nerve, par exemple...
       • light receptor cells in the retina of the eye
       • sound receptors in the ear
       • position receptors in the inner ear
       • chemical receptors in the nose and tongue
       • touch, pressure, temperature and pain receptors in skin
     • receptors respond to a stimulus and send an impulse along SENSORY NEURONS to the CENTRAL NERVOUS SYSTEM
   • Simple Reflexes
     • simple reflexes produce rapid INVOLUNTARY RESPONSES to a stimulus
       • this gives an animal the highest chance of survival
       • यथा...
         • moving towards and finding food
         • moving away and sheltering from predators
         • moving towards and finding a mate
         • pupil dilation
         • babies sucking nipples when said nipples are placed inside said babies' mouths
         • knee jerk reflex
     • mostly used by 'simple' animals (eg. amoeba blublublub)
   • Effectors
     • EFFECTOR: an organ or cell that acts in response to a stimulus
       • either glands or muscles (in multicellular organisms)
     • carry out the body's response to stimuli

2. The Nervous System

3. Conditioned Reflex Responses

4. Complex Behaviour