• Homeostasis?(maintaining controlled conditions within the body) is under?involuntary (automatic) control
• This means that the brain stem (or?non-conscious?part of the brain) and the spinal cord are involved in?maintaining homeostasis?– you don’t consciously maintain your body temperature or blood glucose level
• These automatic control systems may involve?nervous responses?or?chemical responses?(e.g. via?hormones)
• All control systems that carry out co-ordinated responses require the following:
  • A?stimulus?(a change in the environment e.g. a change in glucose levels in the blood, a change in body temperature etc.)
  • A?receptor?(receptor cells that detect stimuli)
  • A?coordination?centre?(such as the brain, spinal cord and pancreas), which receives and processes information from receptors
  • An?effector?(a muscle or gland), which brings about responses to restore optimum levels

   

A co-ordinated response (such as that required when there is not enough water in the blood) requires a stimulus, a receptor and an effector

轉載自savemyexam