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Flashcards in Nerves 3 Deck (22):
1

What is the threshold potential?

About -55mV

2

What will happen when the membrane potential hits -55mV?

An action potential will be fired

3

What is a generator potential?

A graded potential occurring at sensory nerves

4

What is an EPSP?

A generator potential that will depolarise the cell

5

What is a IPSP?

A generator potential that will hyperpolarise the cell

6

What is the graded potential between a motor neurone and a muscle called?

End plate

7

What is the function of graded potentials?

To decide whether or not the stimulus is great enough for a response

8

4 examples of graded potentials

- Generator
- Post synaptic
- Endplate
- Pacemaker

9

4 key properties of graded potentials

- Excitatory
- Non-propegating
- Decremental
- Local

10

Why are graded potentials decremental?

The current leaks out of the cell as it travels down it

11

What is shown by the amplitude of a graded potential?

Signal intensity

12

How can graded potentials generate an IPSP?

- Opening Cl channels on the post synaptic neurone

13

How are fast IPSP's generated?

- Opening ionotropic Cl channels

14

How are slow IPSP's generated?

- By binding to g-protein coupled receptors that open potassium channels causing K to leave the cell

15

What 2 neurotransmitters will trigger an IPSP?

- Glycine
- GABA

16

How are fast EPSP's generated?

- Opening Na/K channels

17

How are slow EPSP's generated?

- Blocking potassium channels that cause potassium to leave the cell

18

What is meant by the fact that graded potentials can summate?

- Two excitatory/inhibitory signals can add to each other

19

What is temporal summation?

Input from the same stimulus add up to each other (turning on a tap, turning it off, then turning it back on again)

20

What is spatial summation?

2 different stimuli add to each other (turning on 2 taps at the same time)

21

What is synaptic integration?

- All inputs taken into consideration
- Action potential decided

22

Why do synapses nearer the axon hillock have a better chance of generating an AP?

- Decremental aspect
- Have to travel less distance so less signal is lost
- Axon hillock is what decided to fire an AP