Nerves

Question 1

What is the action potential of a nerve?

Answer 1

It creates a signal through the nerve to make quick communications throughout the body.

Question 2

What is the threshold of excitation of the nerve? What is the value of this threshold?

Answer 2

It’s the threshold that must be reached to create a action potential. -55mV.

Question 3

What is an “all or nothing” response?

Answer 3

It is the response to the threshold of excitation being reached, which creates a action potential within the nerve.

Question 4

What ions are located within the neuron?

Answer 4

Potassium ions (K+) and negatively charged proteins.

Question 5

What ions are located outside of the neuron?

Answer 5

Sodium ions (Na+) and Chloride ions (Cl-) .

Question 6

What is the charge or the resting phase?

Answer 6

≈ -70mV

Question 7

What is the charge of the peak of the rising phase?

Answer 7

≈ +50mV

Question 8

What happens in hyperpolarization?

Answer 8

The potassium gates close and the membrane within the neuron becomes extra polarized, (extra negative), and the sodium/postassium pumps allow ions to flow through, which compensates for the extra negativity within the neuron.

Question 9

What are sodium/potassium pumps?

Answer 9

They are pumps that utilize active transport to move ions in and out of the membrane. It uses 1 ATP for every 3 Na+ and 2 K+.

Question 10

What does myelin do to the signal of the neuron?

Answer 10

It allows the signal of the neuron to move quicker, by insulating the axon.

Question 11

What is a dendrite?

Answer 11

They recieve the singals from other neurons. They are essentially brances that are connected to the nerve cell body.

Question 12

What is an axon?

Answer 12

The axon is the main branch that sends the signal towards the effector. It is in between the nerve cell body and the axon terminals*.

*The presynatptic neuron

Question 13

What is a Node of Ranvier?

Answer 13

The Node of Ranvier is the gap between myelin along the axon. The space contains sodium and potassium gates.

Question 14

What is a Schwann Cell?

Answer 14

It is the cell that produces the myelin around the axon.

Question 15

What is Myelin?

Answer 15

Myelin is an insulating protein produced by the Schwann Cells. It allows for the signal from a neuron to travel faster.

Question 16

What is the postsynaptic membrane?

Or the postsynaptic neuron

Answer 16

It is the part of the neuron that comes after the synaptic cleft*. It receives signals via neurotransmitters (vesicles) that attach to the receptors.

*Synaptic cleft = Synaptic gap

Question 17

What is the synaptic knob?

Or the the presynaptic neuron..

Answer 17

It is the part of the neuron that comes before the synaptic cleft*. It contains thousands of neurotransmitters that allow for an action potential to be communicated to other neurons.

*Synaptic cleft = Synaptic gap

Question 18

What is an excitatory neurotransmitter?

Answer 18

It is a neurotransmitter that promotes a nerve impulse within the dendrite by allowing sodium to flow.

Question 19

What is a inhibitory neurotransmitter?

Answer 19

It is a neurotransmitter that hinders a nerve impulse within the dendrite by hyperpolarizing the neuron.

Question 20

What effect does Dopamine do to your body and to your nerves?

Answer 20

It allows your nerves to communicate more freely and gives you a “feel-good” effect. It is secreted within the CNS.

Question 21

What effect does Seritonine have on your body and on your nerves?

Answer 21

It controles your mood and helps you think. It has an inhibitory effect on your nerves.

Question 22

What effect does glutamate have on your body and on your nerves?

Answer 22

It