Neurons Potential

Question 1

Recording the membrane potential

Answer 1

Difference in electrical change between inside and outside of cell

Question 2

Resting membrane potential is about…..

Answer 2

-70mV

Question 3

Neurotransmitters bind at…..

Answer 3

postsynaptic receptors.

Question 4

When neurotransmitters molecules bind to postsynaptic receptors, one of TWO effects might happen. What are the effects?

Answer 4

Depolarisation (decrease the resting membrane potential; -70 to -67mV)

Hyper polarisation (increase the resting membrane potential; -70 to -72mV)

Question 5

Postsynaptic Depolarisations are called…..?

Answer 5

Excitatory postsynaptic potentials (EPSP)

- increase probability that the neutron will fire.

Question 6

Hyper polarisations are called……?

Answer 6

Inhibitory postsynaptic potentials (IPSP)

- decrease the probability that the neutron will fire.

Question 7

What are the TWO mechanisms for terminating neurotransmitter action in the synapse…..?

Answer 7

Re-uptake (transporter) and enzymatic degradation (deactivating enzyme).

Question 8

Specific places (pores) for unequal distributions of Na+ and K+ can pass are called……?

Answer 8

Ions channels.

Question 9

TWO types of pressure on Na+ ions to enter the resting neurons are?

Answer 9

Electrostatic pressure and random motion pressure.

Question 10

How does electrostatic pressure on Na+ work?

Answer 10

-70mV in resting membrane potential attracts the opposite charges; Na+ into the resting neurons.

Question 11

How does random motion pressure on Na+ work?

Answer 11

Move down the concentration gradient.

Constant random motion makes particles become evenly disseminated and tend to move down their concentration gradient by moving to low concentration areas from high concentration areas.

Question 12

Why Na+ under both pressures not come rushing into neurons, thus reducing the resting membrane potential?

Answer 12

It’s because sodium ion channels are closed, reducing the flow of Na+ ions into the resting neurons.

The potassium ion channels are open but only a few K+ ions can exit there resting neurons because being held by the negative resting membrane potential (-70mV)

Question 13

Some Na+ ions managed to enter the resting neutrons and some K+ ions managed to exit. Why/ how does the resting membrane potential stay fixed?

Answer 13

Because of ‘sodium-potassium pump’.

At the same rate, some Na+ ions managed to enter the resting neurons, some other managed to get out.

and at the same time, at the same rate, some K+ ions managed to exit from resting neurons and some other managed to get in.