2j coord and response Flashcards
1
Q
define homeostatis
A
maintaneince of a constant internal environent = body water content and temp
2
Q
describe the process of synapses
A
- electrical impulse travels along axon
- triggers nerve-ending of nuerone to release the chemical messengerss = neurotransmitters
- neurotransmitters diffuse across synape and bond w receptor molecules on next neruone
- receptor moleucles bidn only to the specific neurotransmitters released
- stimulates the recieving neurone to transmit the electrical ip
3
Q
optic nerve
A
carries the impulse from retina to brain
4
Q
retina
A
made up of light sensitive reeptor cells = rode and cone cells
convert light –> electrical energy
5
Q
rod cells
A
sensitive to low light intensity
MORE sensitive > cones
6
Q
cone cells
A
sensitive to colour
7
Q
sclera
A
tough outer layer of eye
protects eye and holds it in place
8
Q
cornea
A
-transparent sclera at the front
- refracts light, bending it to enter the eye
9
Q
iris
A
- has a set of muscles that control the size fo the pupil
- regulates amnt of light reaching retina
10
Q
cilliary + suspensory
A
- changes shape of lens to focus lightrays on retina
11
Q
choroud
A
- underneath sclera
- dark layer contains pigment cells + bv which stop light from being reflected aorund inside
12
Q
fovea
A
centre of retina, highest cones conc
13
Q
blidn spot
A
no rods and no cones
14
Q
lens
A
focuses light rays on retina
15
Q
pupil
A
hole in the iris
allows light to pass through
