Neurons and Synaptic Transmission

Question 1

What are the three assumptions of biopsychologists?

Answer 1

• behaviour caused by activity in the nervous system
• nervous system transmit signals for communication via nerve cells
• nerve cells communicate with each other through electrical and chemical messages

Question 2

Define neuron:

Answer 2

Nerve cells process and transmit messages through electrical and chemical signals

Question 3

Define nucleus:

Answer 3

The control centre of a cell, which contains the cell’s chromosomal DNA

Question 4

Define dendrites:

Answer 4

Receives the nerve impulse or signal from adjacent neurons

Question 5

Define axon:

Answer 5

Where the electrical signals pass along.

Question 6

Define myelin sheath:

Answer 6

Insulates /protects the axon from external influences that might effect the transmission of the nerve impulse down the axon.

Question 7

Define Nodes of ranvier:

Answer 7

These speed up the transmission of the impulse by forcing it to ‘jump’

Question 8

Define terminal buttons:

Answer 8

Terminal buttons send signals to an adjacent cell.

Question 9

What are the three types of neurons?

Answer 9

• Motor neuron
• Relay neuron
• Sensory neuron

Question 10

What is the function of the motor neuron?

Answer 10

Carries messages from the CNS to effectors such as muscles and glands

Question 11

What is the length of the fibres of the motor neuron?

Answer 11

Short dendrites and long axons

Question 12

What is the function of the relay neuron?

Answer 12

Transfers messages from sensory neurons to other interconnecting neurons or motor neurons

Question 13

What is the length of the fibres of the relay neuron?

Answer 13

Short dendrites and short axons

Question 14

What is the function of the sensory neuron?

Answer 14

Carries messages from the PNS to the brain and spinal cord

Question 15

What is the length of the fibres of the sensory neuron?

Answer 15

Long dendrites and short axons

Question 16

What part of the nervous system stimulates the reflex arc?

Answer 16

Peripheral Nervous System

Question 17

What sub-unit of the peripheral nervous system stimulates the reflex arc?

Answer 17

Somatic nervous system

Question 18

Describe the reflex arc?

Answer 18

• Receptor
• Sensory neuron
• Relay neuron
• Motor neuron
• Effector

Question 19

Describe the synaptic transmission:

Answer 19

• Nerve impulse travels down axon
• Nerve impulse reaches presynaptic terminal
• Triggers the release of neurotransmitters
• The neurotransmitters are fired into the synaptic gap
• Neurotransmitter binds with receptors on the dendrite of the adjacent neuron
• if successfully transmitted the neurotransmitter is taken up by the post-synaptic neuron
• The message will continue to be passed in this way via electrical impulses

Question 20

Define synaptic transmission:

Answer 20

-Neighbouring neurons communicate across synapse cleft by chemical signals

Question 21

Define neurotransmitter:

Answer 21

Chemicals released from a synaptic vesicle into the synapse by neurons

• Affect transfer of an impulse to another nerve/muscle
• Taken up into the terminal buttons of neurons
• Or broken down by an enzyme

Question 22

What can synaptic connections be?

Answer 22

Excitatory or Inhibitory

Question 23

What causes the excitatory or inhibitory?

Answer 23

The action of the neurotransmitter at the postsynaptic recepto

Question 24

How does the excitatory impact the firing of the next neuron?

Answer 24

More likely

Question 25

How does the inhibitory impact the firing of the next neuron?

Answer 25

Less likely