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Flashcards in excitable heart Deck (26):
1

SA node

- unstable phase 4
- automaticity

2

transmembrane conductance

- POTASSIUM

3

UNGATED POTASSIUM CHANNEL

- constant
- concentration dependent
- it is happening all the time

4

VOLTAGE GATED SODIUM CHANNELS

- not constant
- based on electrical charges
- affected by action potential

5

VOLTAGE GATED CALCIUM CHANNELS

- not constant

6

VOLTAGE GATED POTASSIUM CHANNELS

- not constant

7

Na+ permeability

- fast channel

8

Ca2+ permeability

- slow channel

9

K+ permeability

- slow channel

10

membrane potential (Inside the cell)

-90mV due to potassium going out NORMALLY
- it becomes positive when sodium goes IN

11

Calcium2+ L type channels

- stays plateau positive
- going IN

12

Phase 0

- fast channels open gNa
- depolarization
- opens and close quickly

13

Phase 1

- slight repolarization
- due to transient Potassium current
- closing of the sodium channels

14

arrhythmia

treatment to lower mortality beta blockers not anti arrhythmic drugs because it is also a pro drug

15

Phase 2

- L-type Ca2+ are open
- Calcium influx (maintains the interior +)
- K channels are closed and leaving efflux
- CALCIUM channel antagonist shorten the plateau (NIFEDIPINE, NICARDIPINE, AMLODIPINE ETC) stops the calcium going IN
- POTASSIUM channel antagonist lengthen the plateau (

16

hyperpolarized

- becomes more negative from -70 to -90

17

lethal injection

- sudden depolarization of the heart
- K

18

Phase 3

- L type Ca2+ channel closes gCa
- large K efflux
- cells quickly repolarized

19

Phase 4

- gK high
- voltage gated and unrated potassium channels open
- relative refractory period

20

SA node

- top of the atrium

21

AV node

- bet the atria and ventricle

22

nodal channel

- no phase 1 and 2

23

acetylcholine

- vagal stimulation

24

beta blockers

- blocks the sympathetic stimulation

25

lightheadedness, pulse 40 what is the initial therapy
too slow speed up by

- atropine (anitcholinergic)
- anti vagal stimulation
- anti parasympathetic
- stimulate sympathetic

26

rapid atrial fibrillation initial therapy
too fast slow it down with

- beta blockers to slow down
- stimulate parasympathetic