| what is homeostasis? | homeostasis is the regulation of conditions inside the body to maintain a stable internal environment, in response to both internal and external. |
| how do our cells stay 37 degrees in all types of weather? | our body uses automatic control systems.
which is when our body recognizes when there is a change from optimal conditions and sends a signal to reverse the change. so the levels go back to normal. |
| what are the three main components of automatic control systems? | receptors
- detect a change
such as a rise in temperature
coordination centres such as the brain and spinal cord
-interpret that change
-what needs to be don?
effectors
- carry out the change
such as muscles or glands which release hormones |
| how do we send signals between the three main components of the automatic control system? | we use our nervous system and endocrine system.
the nervous system sends very fast and precise electrical impulses through nerves which allows us to respond to things very quickly such as when we touch a sharp object.
the endocrine system relies on hormones(small chemicals released into the bloodstream). Although they travel around the entire body they only affect certain cells that have the right receptors.
the endocrine system is slower, longer-lasting and more generalised than the nervous system. |
| how does negative feedback work? | whenever something gets too high for example the level of glucose in our blood the negative feedback decreases it again to turn it to normal but if it got decreased too much then the negative feedback will increase it again to make it go back to normal. But if it goes high then the same thing will happen all over again. |
| what is an example of this in real life? | if you walk into a room and it's too cold. The low temperature will be detected by receptors such as in our skin and the nervous system will then send the information to the coordination centre such as the brain and spinal cord these interpret the information then send another set of signals to the effectors such as our muscles that can carry out the useful response like shivering. after a bit of time the shivering will increase our body temperature and we will return to normal. but if it goes too far and instead of turning to normal, we get too hot. then a different set of receptors detect the heat and send their own signals to our coordination system and then a different group of effectors to carry out their own response which is sweating then our temperature will go back to normal and if we get too cold the same thing will happen all over again. |
