Homeostasis

• Homeostasis


  The tendency to maintain a relatively constant internal environment
• Homeostasis


  • Typically involves negative feedback loops that counteract changes of various properties from their target values, known as set points
• Properties maintained by homeostasis

  • Temperature
  • Concentration of various ions in blood
  • pH
  • Concentration of glucose
• If the values of properties maintained by homeostasis get too high or low, you can end up getting very sick
• How homeostasis is maintained

  1. When you exercise, your muscles increase heat production, nudging your body temperature upward

  2. When you drink a glass of fruit juice, your blood glucose goes up
• Negative feedback loops


  Act to oppose the stimulus, or cue, that triggers them
• How negative feedback loops work

  1. If the level of something rises, control systems are switched on to reduce it again

  2. If the level of something falls, control systems are switched on to raise it again
• Negative feedback mechanisms


  • Usually a continuous cycle of bringing levels down and then bringing them back up so that overall, they stay within a narrow range of what is considered 'normal'