Biopsychology - The Structure And Function Of Neurons

Question 1

What is the role of a neuron?

Answer 1

To transmit signals electrically and chemically to provide the body with its primary source of communication.

Question 2

What is the role of a sensory neuron?

Answer 2

It carries messages from the peripheral nervous system to the central nervous system. They have long dendrites and short axons. They located in the peripheral nervous system in clusters called ganglias.

Question 3

What is the role of a relay neuron?

Answer 3

They connect sensory neurons to motor neurons or other relay neurons. They have short dendrites and short axons. Of all neurons 97% are relay neurons and most are in the brain and visual system.

Question 4

What is the role of motor neurons?

Answer 4

They connect the central nervous system to the factors such as muscles and glands. They have short and long axons. Cell bodies may be in the central nervous system but long axons form part of the peripheral nervous system.

Question 5

What is the structure of a neuron?

Answer 5

Cell body
Dendrites
Axons
Terminal buttons

Question 6

What is the cell body of a neuron?

Answer 6

Includes a nucleus which contains the genetic material of the cell.

Question 7

What is a dendrite?

Answer 7

Branchlike structures that protrude from the cell body these carry nerve impulses from neighbouring neurons towards the cell body.

Question 8

What is an axon?

Answer 8

It carries the electrical impulse away from the cell body down the length of the neuron.
- It is covered in a fatty layer of myelin sheath that protects the axon.
- Gaps in the axon called nodes of Ranvier speed up the transmission of the impulse.

Question 9

What are terminal buttons?

Answer 9

They are at the end of the axon and communicate with the next neuron in the chain across a gap called the synapse.

Question 10

What is electrical transmission and firing of a neuron?

Answer 10

• When a neuron is in arresting state, the inside of the cell is negatively charged compared to the outside.
• When a new one is activated, the inside of the cell becomes positively charged for a split second causing an action potential to occur.
• This creates an electrical impulse that travels down the axon towards the end of the neuron.