CV 3 Myocytes And EP

Question 1

What is pattern of depolarization in heart

Answer 1

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

Question 2

All different areas of cardiac depolarization what

Answer 2

Look more or less alike

Question 3

P
Q
R
T

Answer 3

Atrial depolarization

Depolarization down branch bundles of septum

Ventricular depolarization

Ventricular repolarization

Question 4

Way ventricle depolarizes

Way septum depolarizes

Answer 4

Apex to base

Base to apex

Question 5

Ventricle phases 
4
0
1
2
3
4

Answer 5

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

Question 6

What happens to potassium gate when cell depolarizes

Answer 6

Closes. Open at rest. Not leak channels

Question 7

K channels open when what

Answer 7

Myocyte repolarizes

Not leak channel

Question 8

SA node action potential sequence

Answer 8

4 Na leaks in

0 Slowly depolarizes in phase 0 (funny current)

Upstroke is influx of calcium once over threshold f

3 K out

Question 9

Speed of signal going through av node to bundles and why

Answer 9

Sloe because fibrous tissue separates atria from ventricles

Question 10

How sa node and ventriclular action potential charts differ

Answer 10

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

Question 11

What happens at -60 mv in sa node

Answer 11

Na in faster than k leaving

Question 12

What happens in funny current

Answer 12

Na in slowly depolarizing cell

Question 13

How funny channels are opened

Answer 13

When voltage drops below threshold

Question 14

How all other channels than funny are opened

Answer 14

Voltage above threshold

Question 15

How to change heart rate through funny current

Answer 15

More funny current, depolarize quicker, steeper curve

Question 16

Slow l type and transitory calcium channels result in what

Answer 16

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

Question 17

What forms a dyad

Answer 17

Sarcoplasmic reticulum and t tubule

Question 18

What holds myocytes together

Answer 18

Macula adherens

Question 19

Funny current only works where

Answer 19

SA node

Question 20

Which channel responsible for phase 0

Which responsible for calcium moving in

Answer 20

Fast sodium channel

Slow L type calcium channel

Question 21

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

Answer 21

DHP, ryanodine

Question 22

DHP receptor inhibited by what and upregulated by what

Answer 22

Diltiazem

Adrenergics

Question 23

Ryanodine located where

Gated by what

Contributes to what

Answer 23

SR

Ca

Contraction

Question 24

NCX Exchanger

Where
What ions
Gating
Contributes to what phase

Answer 24

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

Question 25

``` SL Ca ATPase Where When open What ion Contributes to what ```

Answer 25

Sarcolemma Ca, always open using ATP Minor contribution to relaxation

Question 26

SERCA/SR Ca ATPase Where Ion When open What contribution

Answer 26

SR Ca Always, ATP Biggest contribution to relaxation

Question 27

Fast na channels Where they are What ion Gating Contributes to what

Answer 27

T tubule Na Voltage Phase 0

Question 28

K1 inward rectifier Where What ion Gating Contributes to what

Answer 28

Sarcolemma K Closes with voltage Phase 4, closes with depolarization

Question 29

K to transient outward Where When open Contributes to what

Answer 29

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

Question 30

``` Kr rapid delayed K Where What ion Gating Resp for what ```

Answer 30

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

Question 31

``` Ks slow delayed K Where Ion Gating Resp for what ```

Answer 31

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

Question 32

``` Na K ATPase Where What ions Gating Contributes to what ```

Answer 32

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

Question 33

``` Phases controlled by what 0 1 2 3 4 ```

Answer 33

Fast sodium Potassium Calcium in, K out Repolarization, K out K channels open (not leak), hyperpolarized

Question 34

What cause contraction while pumping ca out

Answer 34

Delay

Question 35

What you have to do to close ryanodine receptor

Answer 35

Pump all of calcium out

Question 36

K1 inward rectifier closes when

Answer 36

Cell depolarizes

Question 37

``what goal of transient channel is

Answer 37

Keeping contraction from being too long, makes plateau shorter

Question 38

Phase 3 which channels

Answer 38

Slow delayed potassium channels

Question 39

Inward rectifier closes when

Answer 39

Slightly above nernst potential for K, 30 mv

Question 40

Nernst equation for sodium calcium exchanger

Answer 40

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

Question 41

In phase 4 what is na ca exchanger doing

Answer 41

Shoving ca out

Question 42

What is exchanger doing at -7.2 phase 2

Answer 42

Pull positive into cell 3 na in 1 ca out

Question 43

How digoxin works and effects sodium calcium exchanger

Answer 43

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

Question 44

What does isoproterenol b adrenergic agonist do

Answer 44

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

Question 45

What happens when taking diltiazem

Answer 45

Blocks ventricular ca channel, weaker contraction

Question 46

What ca channel blocker does on L type smooth muscle Heart

Answer 46

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

Question 47

Lead I

Answer 47

Between arms

Question 48

Lead two

Answer 48

Arm to opposite leg

Question 49

Lead 3

Answer 49

Arm to same side leg

Question 50

Where we get maximum r wave

Answer 50

Avf

Question 51

R wave biggest in 1, 2, or 3

Answer 51

Lead 2, looks right arm to left leg

Question 52

What is q wave on ekg

Answer 52

Septal depolarization