Biopsych- neurons and neurotransmission

Question 1

list and define the 5 features of a neuron’s structure

Answer 1

• Dendrites- receive signals from other neurons or sensory receptor cells- connected to
• Cell body- contains genetic info and has a nucleus
• Axon- slender fibre that carry’s impulses in action potential
  myelin shealth- this insulates the axon, to increase speed of electrical impulses
  -Axon terminal the connection from neuron to other neurons or organs - through process of synaptic transmission

Question 2

name the 3 types of neurons

Answer 2

-sensory neurons
-relay neuron
-motor neurons

Question 3

What is the Function of sensory neuron
What cell is it
What happens to the nerve impulses once at the brain
If some don’t go to the brain, where do they go

what are the drendrites and axons like

Answer 3

sensory neurons function is to carry nerve impulses to the CNS (spinal cord and brain)
They are receptor cells
Once the nerve impulse reaches the brain it is translated into sensations
Sometimes the impulses don’t go all the way to the brain to be processed, and stop at the spinal cord e.g. reflexes
Sensory neurons have long dendrites and short axons

Question 4

Function of relay (interconnecting) neurons
where are they found
what are the dendrites and axons like

Answer 4

relay neurons function is to let sensory and motor neurons communicate
Located between brain and spinal cord
Live in between sensory input and motor output

• short dendrites and short axons

Question 5

Where are motor neurons found and what is it’s function
when motor neurons are stimulated what is released

what are the dendrites and axons like

Answer 5

motor neurons are found in the CNS and controls the muscle movement
- when stimulated they release neurotransmitters which bind to receptors on muscles that triggers the response
short dendrites and Long axons

Question 6

define synaptic transmission

Answer 6

process of a nerve impulse passing across a synaptic cleft to another neuron (postsynaptic neuron)

Question 7

describe in 4 points the process of synaptic transmission

Answer 7

1. Action potential travels down axon, and stimulates the vesicles in the pre-synaptic neuron to release neurotransmitters into the synapse
2. This is ‘taken up’ or received by the receptor sites in the post synaptic neuron
3. Then depending on the neurotransmitter received, it either produces excitatory (more likely to fire) which will increase the positive charge or produces inhibitory effects, which will increase the negative charge (less likely to fire) on the post synaptic cell
4. summation is the net effect of the EPSPs and IPSPs si it adds up the pos and neg charged
   - if the threshold is reached the new action potential forms and travels down the next axon

Question 8

define uni- directional

Answer 8

this means that the process of information signaling cannot happen in reverse