Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Phys Exam 2: Ch 11
The Normal ECG
| Question | Answer |
|---|---|
| What is an ECG? | 1. Detecting repetiitive changes in the flow of current thru the heart; 2. These changes correlate w/the cardiac cycle stages. 3. These changes are caused by waves of depolarization & repolarization that flow thru the cardiac muscle w/each heartbeat. |
| What is the P wave? | Depolarization of the atria --> atria contract |
| What is the QRS wave? | Depolarization of the ventricles --> ventricles contract |
| What is the T wave? | Repolarization of the ventricles |
| Where is the repolarization of the atria within an ECG? | Hidden within the QRS wave |
| What is the PQ interval? | From the beginning of the P wave to the beginning of the QRS wave |
| What is the ST segment? | From the end of the S wave to the beginning of the T wave |
| What is the QT interval | From the beginning of the QRS wave to the end of the T wave |
| What is the J point? | At the end of the S wave, when S returns to baseline |
| What do the vectors of the heart represent? | Vectors represent amounts of energy and direction. |
| (Blank) is a measurement of heart vectors as they pass under an electrode | The EKG |
| What causes the downward deflection in an EKG? | When a positive electrical wave is moving away from an electrode |
| What causes the upward wave in an EKG? | When a positive wave moves towards an electrode |
| Describe Lead I | Negative to R arm, Positive to L arm; Measures QRS wave and pulse rate |
| Describe Lead II | Negative to R arm, Positive to L leg |
| Describe Lead III | Negative to L arm, Positive to L leg |
| What is Einthoven's Triangle? | Visually correlates electrode placement and the heart |
| What is Einthoven's Law? | The voltages measured by Lead I and Lead III equal the voltage measured by Lead II |
| If a patient has an enlarged ventricular muscle mass, what will the EKG from Lead I show? | An enlarged QRS wave |
| If a patient has a decreased ventricular muscle mass (ex: from an old MI), what will the EKG from Lead I show? | A reduced QRS wave |
| How do you determine pulse rate from an ECG? | Measure the X-axis length b/n peaks, and calculate at 0.2 sec/dark bar, or 0.04 sec/light bar... OR... Estimate by counting the # of dark bars crossed, and use 300, 150, 100, 75, 60, 50." - Pulse rate at a glance. |
| What is the value of the large squares on the Y axis? What does this measure? | 0.5mV; QRS wave |
| What is the value of the large squares on the X axis? The small squares? What does this measure? | Large squares = 0.2sec, small squares = 0.04sec, it measures pulse rate |
| What is the electrical axis of the heart? | The net vector of all of the vectors of the heart. |
Created by:
hclark86
Popular Physiology sets