Quiz 6

Front 1

whats the resting membrane potential of a neuron

Back 1

-70 mV

Front 2

how do neurons communicate?

Back 2

creating a synapse with an action potential

Front 3

what's an action potential?

Back 3

pulse of electrical activity

Front 4

whats a sodium ions charge?
where are they?

Back 4

positive
space outside a neuron

Front 5

how many ions are inside a neuron

Back 5

very few

Front 6

whats the charge of a potassium ion?
where are they?

Back 6

positive
inside neuron

Front 7

whats an electrical/membrane potential

Back 7

inside of neuron is negative compared to outside

Front 8

whey is a neuron negative compared to outside space

Back 8

more potassium ions leave than sodium ions come in

Front 9

what is membrane potential measured in?

Back 9

mV

Front 10

define depolarizing

Back 10

when a neuron becomes less negative (moves closer to 0 or threshold)

Front 11

define repolarizing

Back 11

when a neuron returns to resting membrane potential
-can occur in + or - direction

Front 12

what's in the membrane of a neuron

Back 12

sodium potassium pumps

Front 13

whats the sodium potassium pump do?

Back 13

3 sodiums in
2 potassiums out

Front 14

how is an action potential created?

Back 14

using the sodium potassium gradients to generate a digital pulse

Front 15

membrane surface of an axon has many _________

Back 15

sodium and potassium channels

Front 16

whats a sodium channel look like at resting membrane potential?

Back 16

-outside closed
-inside open

Front 17

whats a potassium channel look like at resting membrane potential?

Back 17

closed

Front 18

during depolarization what happens with the sodium channel?

Back 18

outside opens and lets the sodium flow in rapidly

Front 19

as depolarization occurs, the sodium channel inside gate does what?

Back 19

slowly closes

Front 20

when the threshold is met, what happens with the potassium channel door?

Back 20

opens and lets potassium out

Front 21

what happens when potassium flows out of a neuron?

Back 21

Repolarization

Front 22

why does hyperpolarization occur?

Back 22

the potassium channel door stays open

Front 23

what happens when the nerve terminal becomes depolarized?

Back 23

neurotransmitters are released

Front 24

what do non-gated channels look like?

Back 24

always open (sodium)

Front 25

what do gated channels look like?

Back 25

open and close conditionally at a rapid rate (voltage gated channels)

Front 26

voltage gated channels

Back 26

open and close by voltage sensitive mechanisms
-open and close at specific membrane potentials

Front 27

what is resting potential?

Back 27

ionic difference across the membrane at a steady state

Front 28

all living cells are surrounded by a plasma membrane composed of

Back 28

a lipid bilayer

Front 29

the lipid bilayer is _______

Back 29

hydrophobic

Front 30

the most important neural pump

Back 30

sodium-potassium pump

Front 31

how do sodium ions move to the outside of the cell? (3 steps)

Back 31

1. 3 sodiums bind to protein channel
2. an ATP provides energy to drive the 3 sodiums out
3. channel stays open and 2 potassiums get loaded then go into the cell

Front 32

when is it impossible to have an action potential?

Back 32

during a refractory period

Front 33

graded potentials are primarily generated by:

Back 33

sensory input

Front 34

how is graded potential different than action potential?

Back 34

graded might not initiate a series of depolarizations along the membrane

Front 35

how does a graded potential turn into an action potential?

Back 35

summating together in time or space to generate a stronger signal

Front 36

what happens at a synapse as far as signal

Back 36

changes from electric to chemical
-the chemical is a neurotransmitter

Front 37

neurotransmitters are released from where? go where?

Back 37

terminal bouton into synaptic cleft

Front 38

when dendrites receive the neurotransmitters, what happens?

Back 38

electrical signals form

Front 39

calcium channels on the bouton are

Back 39

closed

Front 40

when do calcium channels open?

Back 40

when action potential depolarizes the terminal

Front 41

once the calcium fuses the protein, what happens

Back 41

neurotransmitters are released into the synaptic cleft

Front 42

the local depolarization is called an

Back 42

EPSP

Front 43

3 ways the neurotransmitters end the synaptic signal

Back 43

1. wander from the synapse
2. break down into other chemicals
3. are pumped back into the nerve terminal

Front 44

2 things the synaptic vesicle can do after dumping neurotransmitters

Back 44

1. pinch off and fill with new neurotransmitters
2. become part of the nerve terminal
-new synaptic vesicles are formed away from the active zone (recycling the extra membrane)

Front 45

each neuron has about ______ synapses on its dendrites

Back 45

1,000

Front 46

chloride ions do what?

Back 46

hyperpolarize membrane potential which moves it away from the threshold
-IPSP

Front 47

IPSPs and EPSPs occur where?

Back 47

soma

Front 48

what are oligodendrocytes

Back 48

glial cells that provide myelination in the CNS

Front 49

where do channels open and close?

Back 49

along the axon in the Nodes of Ranvier

Front 50

unmyelinated fibers are normally found where?

Back 50

PNS

Front 51

how do signals"jump" thru myelin?

Back 51

saltatory transmission

Front 52

multiple sclerosis

Back 52

caused by an auto immune inflammatory response that damages myelin sheath in the CNS

Front 53

Demyelination normally occurs where with MS?

Back 53

optic nerve
deep white matter around ventricles
cerebellar peduncles
parts of the BS and SC

Front 54

guillain-barre syndrome

Back 54

inflammatory process that begins 1-2 weeks after a viral infection
attacks and damages myelin in PNS

Front 55

5 essential steps for chemical messaging via synaptic transmissions

Back 55

1. synthesis
2. packaging
3. release
4. binding
5. termination

Front 56

whats a type of myelination disorder

Back 56

Multiple Sclerosis
Guillain- Barre syndrome

Front 57

Exocytosis

Back 57

neurotransmitters fuzing with presynaptic membrane and release of neurotransmitters

Front 58

endocytosis

Back 58

vesicle membranes taken back up to be recycled

Front 59

potentiation

Back 59

increases odds of vesicle exocytosis the next time an action potential arrives at the terminal

Front 60

depression

Back 60

depleted vesicle pool decreases the odds of action potentials

Front 61

3 major neurotransmitters

Back 61

GABA
Glutamate
glycine

Front 62

1 EPSP

Back 62

Glutamate

Front 63

2 IPSPs

Back 63

GABA
glycine

Front 64

myesthenia gravis

Back 64

disorder of neurotransmitter transmission
autoimmune disease that blocks neurotransmitters from creating a post synaptic response
the more the muscles move, the weaker they get

Front 65

whats an EPSP

Back 65

excitatory postsynaptic potential
depolarization that brings it closer to threshold

Front 66

whats an IPSP

Back 66

inhibitory postsynaptic potential
hyperpolarizing response that moves away from threshold