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Flashcards in Neural Conduction + Synaptic Transmission Deck (49)
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1

what is membrane potential

differences in electircial charge inside/oustide a cell

2

what is the resting potential

steady membrane potential at -70 mv when neuron is polarized

more Na+ ions outsider cell and k+ ions inside cells

3

what is the sodium potattsump pump

exchanges 3 Na+ ions for every 2 K+ ions as ions across cell membrane

4

what do neurotransmitters do

fired form neurons; diffuse across synaptic cleft and interact with receptor molecules on other neurons to either depolraize/hypoerolarize resting potentials

5

deplorization

decreasing the resting potential; to increase firing (exictation)

6

hyperpolarization

increasing the resting potential= to decrease firing (inhibition)

7

what is an action pottential

1 ms; reversal of membran epotneital from -70 mv to + 50 mv for an electrical signal to occur to an ALL or NOTHING response

happens due to changes of voltage-activated ion channels that open/close in response to changing levels of membrane potential

8

what is the absolute refrtaory period

1-2 ms post-action potential when no AP can be generated

9

what is the relative refratory period

only possible to fire neurons with an ELEVATED stimulation

10

describe how an action potential is propogated

1. neuron at rest= -70 mv
2. intiation of AP (positive charged Na+ charge ENTER= neuron depolarizes)= reaches + 50 mv

3. movement of AP (repolarization of axon to negative charge due to negative ions= k+ ions flood OUT)

4.hyperpolarization (suuuper negative to -90 mv)

5. refratory period (sodium potattisup pump; 3 NA out for 2 K in)

6. back to resting state

11

three stages of an action potential

depoloarization
repolarizaiton
hyperpolarization and refratory period

12

what is PSPs

post-synpatic potential: changes in the membrane potential of the postsynaptic terminal of a chemical synapse.

13

what is spatial summation

how multiple signals are integraed into one response (from ESPS + ISPS)

E1 + E2 signals

14

what is the threshold of exictation

when the sum of depolraization + hyperpolarization is enoughh to depolarize the membrane (around -64 mv)

15

what is saltatory conduction

'jumping cnoduction' whereby an AP travel sdown the nodes of ranvier in myenliated axons to speed up AP

16

what is ESPS

exictatory posynaptic potentials; exicte the threshold of a neuron to openin the voltage-gated Na+ channels to reverse the neuronal potential= DEPLARIZE

17

what is IPSPs

inhibitory postsynaptic potentials = HYPOERPOLARIZE

18

temporal summation

two of the same E1 (e1 + e1)

19

subthreshold

no summation occurs

20

spatial summation

Inhibitory and Exictatory (E1 + I1)

21

process of sodium pottassium pump

1. transports 3 Na+ ions out for every 2k+ ions in during resting potential
2. ions move down a concentration gradient (Na+ ions tend to enter/k+ to leave)

3. negative internal charge= pressures both Na+ and K+ to enter

4. sodium pottassium pump transports 3 Na+ out for every 2+ in

22

what do voltage activated ion channels do

two types: K+ and Na+ channels
they oped/close when changes in membrane potential occur

23

what happens when the ESPS exictes the threshold

1. na+ voltage gated channels open and reverse MP from -70 mv to 50 mv

2. na+ channels close which open the k+ voltaged gated channels

3. voltage gated k+ ions channels stay open untill resting potential levels out

24

how does AP conucdtion differ from ESPS/ISPS

1. axonal conduction is continous (does't grow weaker along axonal membrane); nondecremental

2. axonal potentials are conducted more slowly than PSPs

3. axonal conduction using AP is active whereas IPSP/EPSP is passive

5. axonal condition using AP jumps along neurons (saltatory conduction)

25

membrane charges of depoloarization, reporlarization, hypoerpolarizaton

depolarization= - to +

repolarization= + to -

hyperpolarization= - to veeeryy =

26

synaptic tranmission

how AP arriving at terminal buttons trigger the release of neurotramistters into synampsies that interact with other cells causing exictatory/inhibitatory effects

27

types of synapses

1. directed synapses
2. neurodirected synapses

28

directed synapses

synapses at which the site of NT release + site of NT reception are close in proximity

29

neurodirected synapases

synapses at which the site of release is at some distance from the site of reception

30

how do neurons communicate

using neurotransmitters released into synaptic clefts inducing EPSP or ISPS as they bind onto receptors of post-synaptic membranes