homeostatis

• regulators


  uses internal mechanisms to maintain a relatively constant state
• conformers


  their internal state varies with that of the environment
• avoiders


  may not be capable of internal regulation but can minimize internal variations by avoiding environmental disturbances
• negative feedback


  main regulatory mechanism for homeostasis
• sensor, integrator, and effector

  components of built-in set point
• sensor


  to measure the variable being regulated
• integrator


  compares the sensed information with a set point
• Effector


  the device or process that makes the corrective response
• local control

  at the level of individual cells, tissues, or organs
• whole-body system control

  for more complex responses
• intrinsic controls


  regulated by a single tissue or organ on its own and are self serving for the organ in which they occur
• extrinsic controls


  regulatory mechanisms initiated outside an organ to alter its activity and often involves coordination of two or more organs towards a common goal