NERVES: TRANSDUCTION AND SYNAPSES

Question 1

What is the Action potential?

Answer 1

All or none event

Voltage gated channels

Propagates along a nerve

Question 2

What is Graded Potential?

Answer 2

Local change in membrane potential

Triggering event:

– Receptor: Action of stimulus

• Mechanical, chemical or thermal gated channel

– Synaptic: Post synaptic membrane

Question 3

What is the Graded potentials - receptors?

Answer 3

Transduction at the nerve ending

Conversion of stimulus energy (e.g. mechanical) to electrical energy

By specific channels: – Mechanically sensitive ion channels

– Thermal

Question 4

Label the diagram

Answer 4

Question 5

What are synapses?

Answer 5

One way relay stations from pre- to post-synaptic

Plasticity (means the can change e.g. if damaged)

Mchemical realy station between 2 nerves

• Normally chemical – neurotransmitters

Question 6

What are some types of neurotransmitters which can be released at a synapse?

Why ar neurotransmitters important?

Answer 6

neurotransmitters:

– Glutamate

– GABA

– Gamma-aminobutyric acid

– Acetylcholine

– Serotonin

– Noradrenaline

Neurotransmitters are targets for many commonly used medicines

Question 7

Where does the following happen on this diagram:

• Graded synaptic potential
• Action potential Initiation
• Action potential propagation

Answer 7

Question 8

What is an example of an Inhibitory neurotransmitter ?

Answer 8

GABA

Question 9

What is the Presynaptic inhibition?

Answer 9

Results in decreased neurotransmitter release from presynaptic terminal

Axo-axonal synapse