The Nervous System

Question 1

Components of the CNS

Answer 1

Brain
Spinal cord

Question 2

PNS

Answer 2

Peripheral nervous system

Question 3

Components of the PNS

Answer 3

Sensory neurones

Question 4

Motor neurones

Answer 4

Transmit nerve impulses in only one direction (away from the cell body)

Question 5

Features of motor neurones

Answer 5

Dendrites
Cell body
Axon

Question 6

Axon

Answer 6

Carries the nerve impulse from the cell body

Question 7

Dendrites

Answer 7

Make connections with other neurones

Question 8

Role of the PNS

Answer 8

The PNS carries nerve impulses from receptors that act as the body sensors towards the CNS along sensory neurones

Question 9

The role of the CNS

Answer 9

Takes all information contain in inputs from sensory neurones and processes it
It then sends impulses via motor neurones to effector organs

Question 10

What are nerve impulses

Answer 10

Electrical signals transmitted from the cell body towards the axon terminals

Question 11

Myelin sheath

Answer 11

Consists of Schwann cells which acts in a similar way to the insulation on an electric cable

Question 12

Nodes of ranvier

Answer 12

The small gaps between the Schwann cells

Question 13

Synapses

Answer 13

Connections between neurones

Question 14

Neurotransmitters

Answer 14

Nerve impulses carried across the synapse by chemicals

Question 15

Most common neurotransmitter

Answer 15

Acetylcholine

Question 16

Depolarisation

Answer 16

The reversal of the charge difference

Question 17

Polarisation

Answer 17

Of a nerve or muscle cell refers to the different electrical charges on either side of the plasma membrane caused by active transport of ions

Question 18

Repolarisation

Answer 18

The restoration of the original charge difference

Question 19

Pressure

Answer 19

Receptors detect changes in the blood

Question 20

Temperature

Answer 20

Receptors are located in the skin and in the CNS where they detect the core body temperature

Question 21

Sound

Answer 21

Receptors in the inner ear detect sound waves and so allow us to hear

Question 22

Light

Answer 22

Receptors are located in the retina of the eye and are involved in vision

Question 23

Touch

Answer 23

Receptors are a type of pressure receptor located in the skin allow us to experience a range of sensations

Question 24

Pain

Answer 24

Receptors are located throughout the body.
Their function is to signal to the CNS when injury has occurred

Question 25

Taste

Answer 25

Receptors on the tongue can detect the five main types of taste:
- sweet
- sour
- bitter
- salt
- unami

Olfactory receptors are located in the nasal passage detect smells or scents