the nervous system Flashcards
(12 cards)
what carries nerve impulses towards the cell
dendrites and dendrons
what carries nerve impulses away from the cell
axons
what surrounds some axons and what does it do
myelin sheath which acts as an electrical insulator, speeding up the electrical impulse
what is the structure of a sensory neurone
-one long dendron carries nerve impulses from receptor cells to the body which is located in the middle of the neurone
-one short axon carries nerve impulses from the cell body to the cns
what is the structure of the motor neurone
-many short dendrites carry nerve impulses from the CNS to the cell body
-one long axon carries nerve impulses from the cell body to effector cells
what is the structure of the relay neurone
-many short dendtrites carry nerve impulses from the sensory neurone to the cell body
-an axon carries nerve impulse from the cell body to motor neurones
what is the nervous system made up
neurones which go to all parts of the body
what is a sensory receptor
a group cells which detect a change in your environment different receptors detect different things
Examples of different receptors
eyes detect light
skin detects touch and temp change
What does the CNS do after a receptor detects something
it co-ordinates the response - it decides what to do and tells something what to do
where does the impulse travel via from the CNS
relay neurone
what does the effector do once the impulse has reached it
respond accordingly such as a muscle may contract
