Cardio/Renal Lab 1 Flashcards
1
Q
Depolarization
A
- Na, Ca, K move into the cell
2
Q
Repolarization
A
K moves out of the cell
3
Q
Resting potential (Phase 0)
A
-90 mV
4
Q
Atrial and ventricular cardomyocyte depolarization
A
- Systole (contraction)
5
Q
Resting membrane potentional corresponds to?
A
Diastole (relaxation)
6
Q
Phase 0
A
- Na channels open
- influx of Na
- cell rapidly depolarizes and trigger muscle contraction
7
Q
Phase 1
A
- Na channel closes
- K channels open to removed K+ out of the cells
- Partially repolarized
8
Q
Phase 2
A
- calcium channels open and Ca+ flows into the cell
- cells remains depolarized for 0.3 seconds
- Plateau segment of action potential
9
Q
Phase 3
A
- cell repolarizes
- Potassium channel opens and K+ flows out
- cell returns to resting potential
10
Q
Absolute refractory period
A
- cariomyocytes are unable to generate, propogate or respons to the arriving action potential
11
Q
Relative refractory period
A
- the cell is only able to respons when there is a strong enough stimulus from action potential
12
Q
Electrocardiogram
A
- recording of the electrical activity of the heart
- currents generated can reach to the surface of the chest
- recorded by electrodes
13
Q
P wave
A
- first wave of the ECG
- represents the depolarization of the atrium
- before atrial contraction
- short period after (straight line) allows for ventricular filling
14
Q
QRS complex
A
- depolarization of the ventricles
- Q = depolarization from V septum (left to right)
- R = largest wave, depolarization of the V
- S = final stage of V depolarization
15
Q
T wave
A
- ventricular repolarization
- before the end of ventricular contraction
16
Q
ST segment
A
- zero potential between depolarization and repolarization
17
Q
PQ interval
A
- time between the beginning of the P wave and the beggining of the QRS complex