B3.1

Question 1

central nervous system

Answer 1

the part of the nervous system consisting of the brain and the spinal cord

Question 2

peripheral nervous system

Answer 2

the part of the nervous system containing nerve cells that carry information from or to the spinal cord

Question 3

receptors

Answer 3

groups of specialised cells that detect changes in the environment

Question 4

effectors

Answer 4

any part of the body that produces a response

Question 5

example of sense organs

Answer 5

eyes and ears

Question 6

example of effectors

Answer 6

muscles and glands

Question 7

myelin sheath

Answer 7

fatty white substance that surrounds the axon of some nerve cells

Question 8

axon

Answer 8

long extension of cytoplasm in neurons that conducts nerve impulses away from cell body

Question 9

dendrite

Answer 9

receives nerve impulses from other neurons

Question 10

types of response

Answer 10

-voluntary responses (coordinated by the brain)
-involuntary responses (bypass the brain)

Question 11

types of neuron

Answer 11

-sensory neuron
-motor neuron
-relay neuron

Question 12

what is the path of a sensory neuron?

Answer 12

transmits messages from receptors to CNS

Question 13

what is the path of a motor neuron?

Answer 13

transmits messages from CNS to effectors

Question 14

what is the path of a relay neuron?

Answer 14

transmits messages from sensory neurons to motor neurons

Question 15

synapse

Answer 15

-two neurons do not make direct contact
-where they meet, there is a very small gap called a synapse
-neurotransmitters diffuse across the gap between two neurons to carry the signal

Question 16

explain why reflexes are faster than conscious thoughts

Answer 16

they just go through the spinal cord instead of travelling up the spinal cord to the brain and back to the motor neuron, they don’t have as far to travel