Action Potential

Question 1

what is an action potential

Question 2

All cells have similar membrane potential

Answer 2

false

Question 3

hyperpolarization

Answer 3

goes below resting potential

Question 4

depolarization

Answer 4

gets more posituve

Question 5

repolarization

Answer 5

gets more negative

Question 6

Is the axon hillock a graded potential

Answer 6

No

Question 7

what is a graded potential

Answer 7

specialized, localized on a membrane, small change in M potential, passive current flow, varying size, don’t spread far

Question 8

which potential is usually triggered by opening/closing of ligand-gated ion channels

Answer 8

graded

Question 9

bigger rock makes a bigger splash

Question 10

what is the threshold

Answer 10

-55

Question 11

resting potential

Answer 11

-70

Question 12

action potential

Answer 12

at the hillock +30

Question 13

looks the same everytime, once the signal reaches -55, it pops up to action potential

Question 14

Voltage-gated Na+ channel

Question 16

When potassium leaves the cell

Answer 16

negative membrane potential

Question 17

slow moving Voltage-gated K+ channels are also activated at -55 mV. Is this a problem?

Answer 17

no, because its DELAYED, so the sodium leaves first, so when K+ finally leaves the cell depolarizes

Question 18

Changing permeability

Answer 18

can change the charge or action potential

Question 19

all or none laws

Question 20

lidocaine

Answer 20

It corks the voltage-gated sodium channel. Turns off sodium permeability and the action potential can’t go off

Question 21

Trigeminal nerve

Answer 21

teeth, back of mouth dentists inject lidocaine into it

Question 22

Absolute refractory period

Answer 22

can not generate action potential with any amount of stimulus in the world, waits until -55 and sodium gates open in axon (miliseconds)

Question 23

Relative Refractory period

Answer 23

harder to generate action potential, but possible with a large stimulus

Question 24

contiguous conduction

Answer 24

very permeable

Question 25

myelination

Answer 25

a lot faster

Question 26

glial cells

Answer 26

mylenate axons

Question 27

schwann cells

Question 28

nodes of Ranvier

Answer 28

tons of voltage-gated machinery

Question 29

saltatory conduction

Question 30

mylenated vs unmylenated

Answer 30

200 mph vs 4.5 mph

Question 31

sharp pain vs slow achey pain

Answer 31

mylenated vs unmylenated

Question 32

Multiple schlerosis

Answer 32

Caused by autoimmune attack of myelin. Scarring (sclerosis) forms where the myelin is damaged. Inflammation causes degeneration of axons Results in tingling, numbness, balance & coordination problems, gradual paralysis