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Flashcards in CV 3 Myocytes And EP Deck (52):
1

What is pattern of depolarization in heart

SA to AV through atria
To bundle of his
To right and left bundle
To purkinje

2

All different areas of cardiac depolarization what

Look more or less alike

3

P
Q
R
T

Atrial depolarization

Depolarization down branch bundles of septum

Ventricular depolarization

Ventricular repolarization

4

Way ventricle depolarizes

Way septum depolarizes

Apex to base

Base to apex

5


Ventricle phases
4
0
1
2
3
4

4- resting membrane potential, recovery
0- quick upstroke, na in rapidly
2- calcium in during plateau
3- k flows out, repolarization

6

What happens to potassium gate when cell depolarizes

Closes. Open at rest. Not leak channels

7

K channels open when what

Myocyte repolarizes

Not leak channel

8

SA node action potential sequence

4 Na leaks in

0 Slowly depolarizes in phase 0 (funny current)

Upstroke is influx of calcium once over threshold f

3 K out

9

Speed of signal going through av node to bundles and why

Sloe because fibrous tissue separates atria from ventricles

10

How sa node and ventriclular action potential charts differ

In SA node no 1 and 2, no plateau, just depolarization and repolarization

11

What happens at -60 mv in sa node

Na in faster than k leaving

12

What happens in funny current

Na in slowly depolarizing cell

13

How funny channels are opened

When voltage drops below threshold

14

How all other channels than funny are opened

Voltage above threshold

15

How to change heart rate through funny current

More funny current, depolarize quicker, steeper curve

16

Slow l type and transitory calcium channels result in what

Calcium channel open, comes in cell, depolarization rapid but not as fast as sodium

17

What forms a dyad

Sarcoplasmic reticulum and t tubule

18

What holds myocytes together

Macula adherens

19

Funny current only works where

SA node

20

Which channel responsible for phase 0

Which responsible for calcium moving in

Fast sodium channel

Slow L type calcium channel

21

What is the subunit of the slow l type calcium channel that opens ___ receptors which contribute to contraction

DHP, ryanodine

22

DHP receptor inhibited by what and upregulated by what

Diltiazem

Adrenergics

23

Ryanodine located where

Gated by what

Contributes to what

SR

Ca

Contraction

24

NCX Exchanger

Where
What ions
Gating
Contributes to what phase

Sarcolemma, t tubule
1 Ca 3 Na
Always open
To phase 1 dip, relaxation

25

SL Ca ATPase
Where
When open
What ion
Contributes to what

Sarcolemma
Ca, always open using ATP
Minor contribution to relaxation

26

SERCA/SR Ca ATPase

Where
Ion
When open
What contribution

SR
Ca
Always, ATP
Biggest contribution to relaxation

27

Fast na channels

Where they are
What ion
Gating
Contributes to what

T tubule
Na
Voltage
Phase 0

28

K1 inward rectifier

Where
What ion
Gating
Contributes to what

Sarcolemma
K
Closes with voltage
Phase 4, closes with depolarization

29

K to transient outward

Where
When open
Contributes to what

Sarcolemma
Opens with voltage
Contributes to phase 1 dip, closes quickly

30

Kr rapid delayed K
Where
What ion
Gating
Resp for what

Sarcolemma
K
Opens with voltage
Repolarization in phase 3, opens slowly

31

Ks slow delayed K
Where
Ion
Gating
Resp for what

Sarcolemma
K
Opens with voltage
Repolarization in phase 3, opens slower than Kr

32

Na K ATPase
Where
What ions
Gating
Contributes to what

Sarcolemma
3 na 2 k
Always open using ATP
Na K ATPase, inhibited by digoxin

33

Phases controlled by what
0
1
2
3
4

Fast sodium

Potassium

Calcium in, K out

Repolarization, K out

K channels open (not leak), hyperpolarized

34

What cause contraction while pumping ca out

Delay

35

What you have to do to close ryanodine receptor

Pump all of calcium out

36

K1 inward rectifier closes when

Cell depolarizes

37

``what goal of transient channel is

Keeping contraction from being too long, makes plateau shorter

38

Phase 3 which channels

Slow delayed potassium channels

39

Inward rectifier closes when

Slightly above nernst potential for K, 30 mv

40

Nernst equation for sodium calcium exchanger

61 x log (na out/na in)^3 x (ca in / ca out) mv

41

In phase 4 what is na ca exchanger doing

Shoving ca out

42

What is exchanger doing at -7.2 phase 2

Pull positive into cell 3 na in 1 ca out

43

How digoxin works and effects sodium calcium exchanger

Inhibits sodium potassium pump= na in cell is higher. More negative rmp. Spend more time bringing calcium in, sodium concentration higher

44

What does isoproterenol b adrenergic agonist do

Up regulate l type ca exchanger, more ca in and stronger contraction

45

What happens when taking diltiazem

Blocks ventricular ca channel, weaker contraction

46

What ca channel blocker does on

L type smooth muscle

Heart

Dilation, increase co from less resistance, BP lowers, feel weak

Ca influx to sa node decreases, decrease heart rate. Less force of contraction because less ca in ventricle. Heart rests

47

Lead I

Between arms

48

Lead two

Arm to opposite leg

49

Lead 3

Arm to same side leg

50

Where we get maximum r wave

Avf

51

R wave biggest in 1, 2, or 3

Lead 2, looks right arm to left leg

52

What is q wave on ekg

Septal depolarization