Karius - everything Flashcards

1
Q

what does the Na+/K+ pump?

A

3 Na out

2 K in

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2
Q

if nernst is greater (abs value) which gradient dominates?

A

chemical

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3
Q

what kind of channels are Cl?

what nt’s bind to open the channel?

A

Ligand-gated

GABA and Glycine

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4
Q

what controls which way ions flow through a channel?

A

ionic gradient

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5
Q

describe the ClC1 channel

A

open at rest

closes with depol

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6
Q

what are are the sodium channels like during threshold?

A

all of them are open

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7
Q

is it possible to get an AP during absolute refractory period?

A

NO

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8
Q

what happens in a relative refractory period?

A

harder to get 2nd AP, some Na channels back to closed state

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9
Q

what is a depolarization block?

A

voltage inactivation

something external is holding Vm more depol than normal ie. drug

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10
Q

how do most APs travel?

A

via saltatory conduction

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11
Q

what is the result of hyperkalemia?

A

high K+ in ECF, renal failure, may see a depolarization

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12
Q

what is conduction velocity = to?

A

mm / time

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13
Q

do AP die away with time or distance?

A

NO

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14
Q

what is used in direct electrical/chemical communication?

what is the route of transmission?

A

gap junctions

Intracellular fluid

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15
Q

what are the post-synaptic specializations?

A

extensive surface area

post-synaptic densities (NT receptors)

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16
Q

what are presynaptic specializations?

A

mitochondria
vesicles
increased surface area

17
Q

what are the adrenergic nts?

A

SEND H

serotonin
epi
norepi
dopamine
histamine
18
Q

excitatory a.a.?

A

glutamate

aspartate

19
Q

inhibitor a.a.?

A

glycine (spinal cord, brainstem)

GABA (CNS)

20
Q

describe nt release

A
depol of pre-synaptic term
opening of VG-Ca channels
Ca influx into terminal
binding of Ca
conformation change in proteins brings docked vesicles
fusion of vesicular membrane with CM
creation of fusion pore
diffusion of nt into cleft
21
Q

how is nt remvoed from cleft?

A

diffusion
natural (NO)
enzymatically via AChE
Re-uptake via Epi/NorEpi

22
Q

what happens if the nt opens a Na or Ca channel?

what is the nt?

A

depol
then EPSP

ACh or EAA

23
Q

what happens if nt opens a Cl channel?

what is the nt?

A

Cl enters cell
hyperpol

IPSP

GABA or glycine

24
Q

describe temporal summation

A

axon has multiple AP traveling with it

both + or both -

25
describe spatial summation
2 or more synapses simulatenously active | EPSP and IPSP can be ADDED
26
what is located on the T-tubule?
DHP receptor
27
where is the ryanodine receptor located? are they voltage gated?
terminal cisternae (SR) NO
28
with depol of the t-tubule membrane, what happens?
Ca is released from the SR and diffuses to area of myofibrils
29
at rest what is blocking the active sites?
tropomyosin
30
how is tropomyosin moved out of the way?
Ca binds troponin C, it undergoes conformational change and moves tropomyosin out of the way
31
what happens after tropomyosin is out of the way?
Pi will dissociate from the myosin head
32
what happens after Pi dissociates?
ADP dissociates to create the powerstroke
33
what happens when ATP binds the myosin head?
conformational change so that myosin and actin dissociate
34
what does energy due to the myosin?
moves the head back into cocked position
35
when does the powerstroke process stop?
no more ATP or Ca Ca-ATPase removes Ca from cytoplasm mechanical forces prevent contraction
36
where is CrP made? ATP production? when is it used?
at myofibril 1:1 during exercise
37
failure to maintain the energy supply causes fatigue do to what?
nt at NMJ used up | inadequate ATP available
38
how is creatine made?
CrP + ADP --> Cr + ATP
39
what 2 things are required for an ionic gradient?
selective cell membrane | Na/K ATPase