Unit 3 - The cells of the nervous system and neurotransmitters at synapses

Question 1

Three types of neurons?

Answer 1

• Sensory neurons
• Inter neurons
• Motor neurons

Question 2

Cell body?

Answer 2

Contains nucleus = control centre

Question 3

Axon?

Answer 3

• Single nerve fibre that carries nerve impulses AWAY from cell body
• Surrounded by myelin sheath (layer of fatty material that insulates axon increasing speed of impulse conduction)

Question 4

Dendrites?

Answer 4

Pass impulses TOWARD cell body

Question 5

Myelination…?

Answer 5

• The development of myelin (from birth to adolescence)
• This is why responses to stimuli during first 2 years of life are not as rapid/coordinated as an adult
• If my

Question 6

What happens if myelin sheath is destroyed by a disease?

Answer 6

Loss of coordination

Question 7

What produces myelin sheath and supports neurons?

Answer 7

Glial cells

Question 8

What is a synapse?

Answer 8

• The region of functional contact between ending of AXON in 1 pre-synaptic neuron and a DENDRITE of another postsynaptic neuron.
• Synaptic cleft is the gap between the two neurons

Question 9

How are messages relayed across synaptic cleft?

Answer 9

Relayed by neurotransmitters stored in vesicles on the presynaptic neuron (like acetylcholine)