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Question 1

Neuron

Answer 1

Neurons can convey information as an electrical signal induced by the cell body
It travels down the axon to its terminal

Neurons use ions to set up potentials
- The difference in voltage between inside and out

Question 2

Axon

Answer 2

a thin fiber that connects neurons (nerve cells) to that they can communicate.

Question 3

Action potential

Answer 3

Outside stimuli triggers sodium channels to open which then increases the charge inside the membrane, which makes it go towards about -55 , then if it hits -55 more sodium gated ion channels open to help de-polarize the cell to about posative 30. then potasium ions re-polarize the cell -70.

Question 4

Graded Potential

Answer 4

a slightly change in potential of a neruon which indavually doesn’t reach the threshold potential ( not enough for a an ation potential)

Question 5

Resting potential

Answer 5

: how neurons hang out most of the time
More negative inside than out, around -70mV
Achieved by keeping certain ions in, pumping others out

Question 6

• Threshold

Answer 6

When the charge reaches the threshod potential dodium channels open and action potential must happen( -55 to -40)

Question 7

Hyperpolarization

Answer 7

: more polarized (<-70)
Happens from K+ leaving or Cl- coming in

Question 8

Depolarization

Answer 8

less polarized (>-70)
Happens from Na+ channels opening

Question 9

Impulse

Answer 9

When a channel opens, it depolarizes the area around it
This deploys the cell enough so that the next one opens
And so on…
This is how a nerve signal travels down a neuron!
Like dominoes (game, not pizza)

Question 10

Schwann cell

Answer 10

grow to loop around and around the axons of neurons

Question 11

Myelin sheath

Answer 11

protects the long, thin neurons
Also insulates them…no ions in or out

Question 12

Node of Ranvier

Answer 12

Those are the spots inbetween the mythene sheet it steps up the saltatory conductins. its the gaps

Question 13

Saltatory conduction

Answer 13

saltatory conduction is where the signal jumps through the myealth sheet and towards the next ion channels

Question 14

Refractory period

Answer 14

Once the threshold potential is reached
K+ channels open, and ions flow back into the cell
This starts to repolarize the cell

Question 15

EPSP

Answer 15

Excitatory post-synaptic potential
- an excitatory postsynaptic potential is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential.

Question 16

IPSP

Answer 16

Inhibitory post-synaptic potential
- An inhibitory postsynaptic potential is a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.

Question 17

Summation
- Temporal

Answer 17

Signals are summated by their time (temporal)

graded potential have to be at the same time or it wont reach the threshold

Question 18

Summation
- Spatial

Answer 18

Signals are summated distance (spatial)
if the sitimilu is not on the same side the body will wont reach its threshold

Question 19

K-
Charge
Movement
Role

Answer 19

Charge: Positive
Movement: Attracted to go into the cell by the A-
But! Are balanced by charge vs. concentration
As concentration increases, prevents more K+ from entering.
Can move freely in and out of the cell

Role: Maintain resting potential
repolarize after Action Potential

Question 20

Na-
Charge
Movement
Role

Answer 20

Charge: Posative
Movement: Na+ is trapped outside
If it comes in, S-P pump takes them right out

Role: Depolarize for the Action Potential

Question 21

Cl-
Charge
Movement
Role

Answer 21

Charge: negative
Movement: can move freelying in and out
Role: Maintin resting potential

Question 22

Protein/A-
Charge
Movement
Role

Answer 22

Charge: negative
Movement: can’t go out of the cell they are too big
Role: Maintain resting potential

Question 23

What direction does a neural signal travel?

Answer 23

Nerve impulses begin in a dendrite, move toward the cell body, and then move down the axon.

Question 24

How does a neuron maintain a resting potential?
????

Answer 24

Negative inside so all the posative ones want to come inside so the K want to go in but here are soon so many Ks they stop wanting to come in and there can be so many that the Ks just start to get pushed out. they are pushed out by th echarage and the concentration of K inside.
-Miantains it also beacuse it prevents sodium from comming in

Question 25

What role do voltage-gated channels play in an action potential?

Answer 25

they open once the thresold is reached and thses chennles open and sodium rushes into the cell causeing the action potential.

Question 26

How does an impulse travel down a neuron?

Answer 26

When a channel opens, it depolarizes the area around it
This deploys the cell enough so that the next one opens
And so on…

Question 27

How does a cell return to resting potential after an action potential?

Answer 27

the soidum gatedion channel shuts this stops sodium commug into cell, then the change in charge opens the potasium channels which allows potassium to flow into the cell, re-polarizing it. ( sodium potatium pump also removes sodium and adds potasium)

Question 28

How does the refractory period limit how often a neuron can send a signal?

Answer 28

during the refacotry period an actiom potential cant happen, since the ions are not in the right place and the channels can’t be activated to switch them. ( sodium on inside and potasium on outside *WRONG)

Question 29

How does a cell body “know” to start an impulse?

Answer 29

When greaded potentials reach threshold. Whens theres enough of a signal to cause it.

Question 30

How can a nerve signal be started from sensory information?

Answer 30

Instead of voltage ion channels there are mechanical Ion channels that open when they are strected. When the hair gets pulled it mulls the membrane opens the channel and a signal is sent.