b10 nervous system

whats the order of the control system

1. stimulus

2. sensory neurone

3. receptor

4. coordination centre

5. motor neurone

6. effector

7. response

what is a stimulus

a change in the environment

what does a receptor do

cells which detect changes in the environment

what does the coordination centre do

receive and process information to coordinate a response

what is an effector

muscles or glands which bring about a response

what two organs is the central nervous system made out of

brain

spinal cord

define hoemostasis

the regulation of internal conditiosn of cells to maintain optimum conditions

what do sensory neurones do

transmit messages from sense receptors to brain or spinal cord

what do motor neurons do

transmit messages from the brain and spinal cord to muscle and glands

what do relay neurones do

carry nerve impulses within the central nervous system

what is a synapse

a junction between two neurones across which electrical signals pass through

how do electrical impulses pass through a synapse

1. along neurone to synapse

2. neurotransmitters are relaeased

3. neurotransmitters diffuse acrsos the synaptic cleft

4. they bind to receptor molecules on the next neurone

5. this triggers a new electrical impulse in the seocn neurone

define reflex action

rapid automatic responses of the nervous system which don’t involve conscious thought

how do reflex actions take place

1. receptor detects a stimulus

2. nerve impulses travel via the sensory neuron

3. relay neurone transmits the impulse

4. motorn neuron transmits the impulse to effector

5. effecto responds to stimulus

what does a relfex arc contain

• snesory neurone

• motor neuron

• relay neuron