1:6:2+1:6:3 Central nervous system

Question 1

What are the three steps of the nervous system. Include examples.

Answer 1

Receptors, Eye (Sight), Ear (Sound), Tongue (Taste), Detects stimulus

Coordinators, Brain and spinal cord, Process information

Effectors, Muscle, Carry out the response

Stimulus>Receptor>Co-ordinator>Effector>Response

Question 2

What is the central nervous system made up of?

Answer 2

Brain and spinal cord. (Both co-ordinators of the CNS)

Question 3

Define stimulus.

Answer 3

Something in our environment that we respond to.

Question 4

What is the role of the brain?

Answer 4

It co-ordinates responses. It needs to be able to receive messages from receptors and send messages to effectors. These travel as electrical signals called impulses along nerve cells or neurones.

Brain also decides which receptors link up with effectors and even whether a stimulus brings about a response.

Question 5

Explain voluntary actions and draw a diagram.

Answer 5

Actions are not automatic, they are deliberate

Processed by the brain, involve conscious thought

Effectors (muscles)

Motor neurones

Spinal cord

Brain

Spinal cord

Sensory neurones

Senses (Eyes)

Question 6

Explain reflex actions and draw a diagram.

Answer 6

Actions aren’t automatic and rapid

Not processed by the brain and only passes through the spinal cord.