Synaptic transmission

Question 1

Simply put, what is synaptic transmission?

Answer 1

The process by which one neuron communicates with another.

Question 2

What causes an electrical impulse to be created?

Answer 2

An action potential.

Question 3

What is the resting state of a neuron cell?

Answer 3

Negative charge.

Question 4

When does an action potential occur?

Answer 4

When a stimulus activates the neuron, disturbing the negative charge.

Question 5

How is information passed down the axon of a neuron?

Answer 5

As an electrical impulse known as an action potential.

Question 6

What happens when the action potential reaches the end of the axon?

Answer 6

It must be transferred to another neuron or tissue.

Question 7

What is the space between the pre-synaptic neuron and the post-synaptic neuron?

Answer 7

The synaptic cleft.

Question 8

Where are synaptic vesicles found?

Answer 8

In the axon terminals (at the end of the neurons).

Question 9

What are held in the synaptic vesicles?

Answer 9

Chemical messengers, known as neurotransmitters.

Question 10

What happens when an action potential reaches the axon terminal?

Answer 10

Synaptic vesicles release their neurotransmitters.

Question 11

Where is the final point which an action potential reaches before the vesicles are released?

Answer 11

The synaptic terminal of the pre-synaptic neuron.

Question 12

What happens when neurotransmitters reach the post-synaptic neuron?

Answer 12

They bind to receptors on the neuron’s membrane.

Question 13

Do the vesicles cross the synaptic cleft?

Answer 13

No, they release the neurotransmitters into the gap but remain on the pre-synaptic neuron.

Question 14

How do the neurotransmitters cross the synaptic cleft?

Answer 14

They diffuse across and bind to receptors.

Question 15

What effect does an inhibitory neurotransmitter have on the post-synaptic neuron?

Answer 15

They reduce the likelihood that the post-synaptic cell will fire.

Question 16

What are the two types of neurotransmitter effects on the post-synaptic neuron?

Answer 16

Excitatory and Inhibitory.

Question 17

What type of neurotransmitter is noradrenaline?

Answer 17

Excitatory.

Question 18

What type of neurotransmitter is GABA?

Answer 18

Inhibitory.

Question 19

What effect does an excitatory neurotransmitter have on the post-synaptic neuron?

Answer 19

They make the post-synaptic cell more likely to fire.

Question 20

Outline the process of synaptic transmission: (4)

Answer 20

• The neuron is activated by a stimulus.
• An action potential occurs creating an electrical impulse.
• The impulse travels down the axon to the synaptic terminal.
• Triggering vesicles filled with neurotransmitters to be released into the synaptic cleft.
• Neurotransmitters reach the receptors on the post-synaptic neuron.
• Signalling for an electrical impulse to be released.

Question 21

What triggers an action potential (electrical impulse) in the post-synaptic neuron?

Answer 21

The binding of neurotransmitters to the receptors on the post-synaptic membrane.

Question 22

What happens to the neurotransmitters left in the synapse?

Answer 22

They are taken back by the pre-synaptic neuron, or are broken down by enzymes.

Question 23

What is meant by the term neural networks?

Answer 23

Groups of neurons communicating with each other.

Question 24

What is the synapse?

Answer 24

A small gap between each neuron in a neural network.

Question 25

How are signals transmitted WITHIN neurons?

Answer 25

Electrically, through an action potential.

Question 26

How are signals transmitted BETWEEN neurons?

Answer 26

Chemically, through neurotransmitters diffusing across the synaptic cleft.

Question 27

What part of the post-synaptic neuron is involved with synaptic transmission?

Answer 27

The dendrites receive the neurotransmitter signals.

Question 28

Where is the chemical message (from neurotransmitters) converted into an electrical message (action potential)?

Answer 28

In the dendrites of the post-synaptic neuron.

Question 29

The fit of a neurotransmitter into a receptor has been likened to a lock and key fit such as an enzyme, explain why?

Answer 29

Each neurotransmitter has a specific molecular structure that fits perfectly into a post-synaptic receptor site.

Question 30

Which neurotransmitter is found where a motor neuron meets a muscle and when released causes a muscle to contract?

Answer 30

Acetylcholine (ACh).

Question 31

What type of neurotransmitter is seratonin?

Answer 31

Inhibitory.

Question 32

Adrenaline is both a hormone and a neurotransmitter, what type of neurotransmitter is it?

Answer 32

Excitatory.

Question 33

Suggest the effects of anti-anxiety medications such as Valium:

Answer 33

They are inhibitory to reduce the chance of firing.