Homeostasis

• Homeostasis 


  is the regulation of conditions inside the body to maintain a stable internal environment in response to internal & external conditions
• automatic control systems

  receptors -> coordination centers -> effectors

  (detect a change) -> (interpret the change and what needs to be done) -> (carry out the change)
• nervous system

  • very fast & precise electrical signals (nerves)
  • responds quickly
• endocrine system

  • releases hormones into the bloodstream
  • slower & longer-lasting
  • more generalised
• thermoregulation


  the control of our internal body temperature (37°C)
• how do our bodies keep us warm

  1. thermostat in the hypothalamus activates warming mechanisms
  2. blood vessels constrict, diverting blood from the skin to deeper tissues (prevents heat loss)
  3. erector muscles also contract, making our hairs stand on end, this can allow for a layer of insulating air to be trapped (reduces heat loss)
  4. skeletal muscles shiver (generates heat)
  5. body temperature rises & the warming mechanisms get shut off
• how do our bodies keep us cool

  1. thermostat in the hypothalamus activates cooling mechanisms
  2. blood vessels expand/vasodilate, and heat radiates from the skin's surface
  3. erector muscles relax
  4. sweat is produced when sweat glands are activated