Homeostasis

• what is homeostasis ?

  • the control or regulation of the internal conditions of a cell or organism
• what are examples of internal conditions in the body ?

  • Water content
  • Temperature
  • pH
  • Blood pressure
  • Blood glucose concentration
• what happens if limits of internal conditions are exceeded ?

  organism may die
• 2 examples of homeostasis in the human body ?

  • control of body temperature
  • control of body water content
• what is the core body temperature of humans ?

  37 degrees
• what are ways the body looses water ?

  • sweating
  • breathing
  • urine
  • faeces
• why is our body temperature kept at 37 degrees ?

  because enzymes in the human body work best at 37 degrees
• what is our body temperature monitored and controlled by ?

  thermoregulatory centre
• where is the thermoregulatory centre ?

  in the base of the brain
• what is the role of the thermoregulatory centre ?

  sensitive to blood temperature in brain receiving messages from temperature receptors in the skin that provide information about skin temperature
• what happens when you are hot ?

  • a lot of sweat is produced
  • energy transferred when sweat evaporates from your skin to the enviroment calming you down
  • blood vessels widen for more energy transferred
  • hairs lie flat
• what happens when you are cold ?

  • very little sweat produced
  • blood vessels constrict , less energy transferred to surroundings
  • shiver more, increasing rate of reaction , warms your body
  • hairs stand on end to trap insulating layer of air , keeps you warm