Topic 6 - organisms respond to changes in their environment

response to stimuli

nervous coordination

Homeostasis

principles of homeostasis

• what is homeostasis

  • the maintanence of an organisms internal environment within set limits

  • it increases the organisms survival chances by modifying their internal environment in response to external changes

• why is homeostasis important

  • enzyme activity - enzymes operate best over a specific range of conditions,

blood glucose regulation

• what are characteristics of hormones

  • produced in glands

  • secreted from the gland and carried in plasma

  • binds to complimentary receptors

  • have widespread and long lasting effectors

• second messengers

  • second messengers relay signals that are recieved at receptors on the cell surface to