homeostasis Flashcards
what is homeostasis
maintaining a stable internal environment
what do cells need to function properly
certain conditions
which certain conditions to cells need to function properly
they cant be too hot
they cant be too cold
they cant be to acidic
they cant be too alkaline
your cells need a good supply of what
glucose
h20
how do we achieve our cells to maintain certain conditions
by our body regulating
what does our body regulating mean
it makes sure our body is kept at the right levels
our body doesn’t keep everything constant, eg what
our temperature and glucose levels fluctuate within small bounds however
what is the full definition of homeostasis
it is the regulation of conditions inside the body to maintain a stable internal environment, in response to both internal and external conditions
being in response to both internal and external conditions means what
we can maintain our internal environment even if changes are taking place outside of our cells
eg if we walk out in the snow or a desert. we can still keep our cells at what
37oc by regulating our body
how does our cells keep its temperature at 37oc by regulating our body
due to automatic control systems
what do automatic control systems do
it recognises when there’s a change from optimal conditions and then it sends a signal to reverse that change so that the levels go back to normal
automatic control systems have which 3 main components
receptors
coordination centres
effectors
what do receptors do
they detect a change
(eg a rise in temperature)
what do coordination centres do
interpret the change and decides what needs to be done about it
(eg spinal chord or brain)
what do effectors do
they carry out the change
(muscles that may contract or glands that can release hormones)
how do we get the 3 components of the automatic control system send signals between them
via the nervous system and the endocrine system
what does the nervous system do
it sends very fast and precise electrical impulses through nerves
what does the nervous system allow you to do
respond to things very quickly
(eg when you touch a sharp object)
what are hormones
small chemicals which are released into the bloodstream
the endocrine system is generally what
slower, longer lasting and more generalised than the nervous system
whenever the level of something gets too high (eg level of glucose in our blood) , what occurs
the negative feedback acts to decrease it again to return it to normal
whenever the level is too low (eg level of glucose in our blood) what occurs
the negative feedback will increase it again returning it to be normal
what essentially does negative feedback do
does the opposite of whatever the change was