B5, homeostasis and response Flashcards
what is homeostasis
the regulation of conditions inside your body (and cells) to maintain a stable internal environment in response to changes in both internal and external conditions
why is homeostasis important
your body and cells need the right conditions in order to function properly
what are automatic control systems
and examples
- they regulate your internal environment
- include both nervous and hormonal communication systems
- e.g there are control systems that control your body temperature, blood glucose levels and water content
what are the main components your automatic control system are made of and why do we have them
- they work together to maintain a steady condition
- made of cells called receptors, coordination centres (including the brain, spinal chord and pancreas) and effectors
what is negative feedback and what does it do
- your automatic control systems keep your internal environment stable using negative feedback
- when the level of something gets too high or too low your body uses negative feedback to bring it back to normal
describe the process of negative feedback when the receptor detects a stimulus level is too high (diagram)
receptor detects a stimulus- a level is too high
the coordination centre receives and processes the information, then organises a response
effector produces a response that counteracts the change and restores the optimum level
the level decreases
describe the process of negative feedback when the receptor detects a stimulus level is too low (diagram)
receptor detects a stimulus - a level is too low
the coordination centre receives and processes the information, then organises a response
effector produces a response that counteracts the change and restores the optimum level
the level increases
what does ‘stimulus’ mean in terms of negative feedback
a change in the enviroment
how long will the effectors produce a response
for as long as they’re stimulated by the coordinate centre
