The cells of the nervous system and neurotransmitters at synapses

Question 1

Name the 2 different types of cells in the nervous system?

Answer 1

1) Neurones
2) Glial Cells

Question 2

Give some info on neurons

Answer 2

• They have a nucleus, cytoplasm and a cell membrane and have specialised features for their function.
• Adapted to carry electrical impulses and they contain long fibres to carry these impulses through the nervous system.

Question 3

What’s the function of sensory neurons?

Answer 3

Transmit impulses from sense receptors to CNS.

Question 4

What’s the function of inter neurons?

Answer 4

Receives impulse from sensory neurone and relays the impulse to the motor neurone – found in the CNS

Question 5

What’s the function of motor neurons?

Answer 5

Transmit impulses from CNS to effector organ.

Question 6

What is the function of this feature: dendrites

Answer 6

Thread-like extensions that receive impulses and conduct these towards the cell body.

Question 7

What is the function of this feature: cell body

Answer 7

Contains the nucleus and other cell organelles. Contains many ribosomes (for enzyme and neurotransmitter production).

Question 8

What is the function of this feature: axon

Answer 8

A fibre that conducts impulses away from the cell body – usually branch at the ends and covered in a myelin sheath. Very long (from CNS in spinal cord to muscles in leg or feet)

Question 9

What is a myelin sheath?

Answer 9

It is a covering made up of cells that contain fatty material that insulates the axon. This increases the conduction speed of nerve impulses.

Question 10

When does Myelination occur?

Answer 10

Continues from birth to adolescence

Question 11

Why are unmyelinated neurones slower at transmitting impulses?

Answer 11

They don’t contain an electrical insulator so the signal/impulse degrades as it goes along the neurone. The strength of the impulse decreases.

Question 12

What impact does this have on younger children?

Answer 12

Responses to stimuli, are not as rapid or coordinated as older children or adults and no thermostat to control their body temp.

Question 13

Certain diseases can damage the myelin sheath.
What impact does this have?

Answer 13

Results in a loss of co-ordination

Question 14

What do glial cells roles include?

Answer 14

· Providing physical support for neurones
· Production of the myelin sheath