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

Function of sensory neuron

Answer 3

sensory neurons= receptor cells carry nerve impulses that go to CNS and are translated into sensations
reflexes show that some impulses don’t go all the way up to the brain, so stop at spinal cord
-Long dendrites and short axons

Question 4

Function of relay (interconnecting) neurons

Answer 4

relay neurons= between sensory input and motor output
allow the CNS to communicate
- short dendrites and short axons

Question 5

Function of motor neurons

Answer 5

motor neurons= 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 int he 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