Biopsychology: Neurons & Synaptic transmission

Question 1

What are neurons?

Answer 1

Nerve cells that process and transmit messages through electrical and chemical signals

Question 2

What are the 3 types of neurons?

Answer 2

• Sensory neuron
• Relay neuron
• Motor neuron

Question 3

Explain the structure of a neuron:
1. What does the cell body contain?
2. What branchlike structures protrude from the cell body? And what do they carry?
3. What carries the impulses away from cell body to end of neuron?
4. What is (3) covered in and what does it do?
5. What final thing does (3) have? What’s the name of it & how does it help?
6. What is at the end of the axon? And what do they do?

Answer 3

1. Nucleus containing genetic material of the cell
2. Dendrites - which carry nerve impulses from neighbouring neurons towards cell body
3. Axon
4. Covered in a myelin sheath - protects axon & speeds up electrical transmission
5. Has segmented gaps (nodes of ranvier) which help speed up electrical transmission as impulses have to ‘jump’ across the gaps along the axon
6. Terminal buttons - communicate with next neuron in the chain across the gap (synapse)

Question 4

Where are sensory neurons found?

Answer 4

Located outside of CNS, in the PNS (known as ganglia)

Question 5

Where are relay neurons found?

Answer 5

Brain & visual system

Question 6

Where are motor neurons found?

Answer 6

• Cell bodies found in CNS
• Their long axons form part of the PNS

Question 7

When does action potential occur?

Answer 7

When a neuron is activated by stimulus

Inside of cell becomes positively charged for split second= action potential

Causes electrical impulses to travel down axon towards end of neuron

Question 9

What does the Sensory neuron do?

Answer 9

• Carry messages from PNS to CNS
• keeps brain informed about external/internal stimuli
• only transmits messages one way
• long dendrites & short axons

Question 10

What does the Relay neuron do?

Answer 10

• Carry messages from sensory neurons to motor neurons or other relay neurons
• carry signals through CNS
• messages can be transmitted or received
• short dendrites & short axons

Question 11

What does the Motor neuron do?

Answer 11

• Carries messages from CNS to effectors in PNS= muscles & glands
• short dendrites & long axons