Biopsychology: Neurons and synaptic transmission

Question 1

Sensory neurons carry information…

Answer 1

from PNS to CNS

Question 2

Relay neurons carry information…

Answer 2

between sensory and motor

Question 3

Motor neurons carry information…

Answer 3

from CNS to effectors

Question 4

Sensory neurons have

Answer 4

long dendrites

short axons

Question 5

Relay neurons have

Answer 5

short dendrites

short axons

Question 6

Motor neurons have

Answer 6

short dendrites

long axons

Question 7

Outline structure of a neuron

Answer 7

• Cell body containing nucleus
• Dendrites = branch like structures which carry impulse from previous neuron
• Axon = carry impulse to next neuron
• Myelin sheath = protects and speeds up transmission
• nodes of ranvier = gaps between myelin sheath

Question 8

Define electric transmission

Answer 8

When a neuron is activated, inside becomes more negatively charged than outside
This causes action potential
Creating electrical impulse that travels down axon towards end of neuron

Question 9

Outline synaptic transmiison

Answer 9

1. electrical impulse reaches end of neuron
2. Neurotransmitter released from vesicles and diffuses across synapse
3. Bind to receptors on post synaptic neuron
4. Chemical message converted back to electrical impulse
5. Can be:
   - Excitation (increases positive charge, action potential likely to fire)
   - Inhibition (decrease in positive charge, less likely to fire)