Neurons

Question 1

What is the structure of a neuron?

Answer 1

Vary in size: less than a millimetre- a metre long.
Cell body (soma) - contains the nucleus (genetic information).
Dendrites - protrude from cell body- carry nerve impulses from neighbouring neurons.
Axon - carries impulses away from cell body. Covered in a fatty layer (myelin sheath- protection).
Nodes of Ranvier - located on myelin sheath- helps impulses “jump” along gaps in the axon.
Terminal buttons - end of the axon, communicate with the next neuron across the synapse (gap)

Question 2

What are the three types of neurons?

Answer 2

Motor neurons
Sensory neurons
Relay Neurons

Question 3

What are motor neurons?

Answer 3

: connect the CNS to muscles & glands. They have short dendrites and long axons.

Question 4

What are the sensory neurons?

Answer 4

these carry messages from the PNS to the CNS. They have long dendrites and short axons

Question 5

What are the relay neurons?

Answer 5

these connect the sensory neurons to the motor/other relay neurons. They have short axons and short dendrites.