B5 Homeostasis (page 58) Flashcards
What is Homeostasis?
Maintaining a Stable Internal Environment.
Why is it important to keep the conditions inside your body steady, even when the external environment changes?
This is really important because your cells need the right conditions in order to function properely. Including the right conditions for enzyme action (see page 25).
What is Homeostasis all about?
its all about the regulation of the conditions inside your body (and cells) to maintain a stable internal environment, in response to changes in both internal and external conditions.
We have loads of automatic control systems in our body that regulate your internal environment, name some?
these include your nervous and hormonal communication systems.
(for example; there are control systems that maintain your body temperature, blood glucose level (see page 63) and your water content).
All your automatic control systems are made up of three main components which work together to maintain a steady condition, what are they?
cells called receptors,
coordination centres ( including the brain, spinal cord and pancreas) and
effectors.
What is meant by negative feedback?
Your automatic control systems keep your internal environment stable using a mechanism called negative feedback.
When the level of something (e.g. water or glucose) gets too high or too low, your body uses negative feedback to bring it back to normal.
What would the process be if Receptor detects a stimulus - level is too high?
1) The coordination centre receives and processes the information then oranises a response.
2) Effector produces a response, which counteracts the change and restores the optimum level - the level decreases.
see diagram on page 58
What would be the process if the Receptor detects a stimulus - level is too low?
1) The coordination centre receives and processes the informaion then organises a response.
2) Effector produces a response, which counteracts the change and restores the optimum level - the level increases.
see diagram on page 58
What do Stimulus mean?
a change in the environment.
The effectors will just carry on producing the responses for as long as they’re stimulated by the coordination centre, why might this be a problem?
This might cause the opposite problem - making the level change too much (away from the ideal). Luckily the receptor detects if the level becomes too different and negative feedback starts again.
(the process happens without you thinking about it - its all automatic.
Why do the internal conditions of your body need to be regulated? (1 mark)
To maintain the right conditions for cells to function properely and for enzyme action (1 mark)
Name the component of a control system that detects stimuli?
Receptor (cell) (1 mark)
