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MLA week 1
MLA week 1 ECG & Cardiac Conduction System
Question | Answer |
---|---|
ECG | ECG # Electrocardiogram = records the electrical impulses that occur in the myocardium during a cardiac cycle. |
The SA node triggers an impulse, the atrial fibers produce an electrial change called a "__" wave | P - wave |
The heart is located in the "______" cavity | Thoracic or chest cavity |
The apex of the heart points towards the | Left Hip |
Give 5 examples why a dr. may order a ECG | After a Myocardial infarction - Symptoms - due to prescribed medications - insertion of a pacemaker - heart condition |
Atrioventrical valves | tricuspid and mitral valves |
5 major vessels | Superior Vena Cava; Inferior Vena Cava; Pulmonary Artery; Pulmonary Veins; Aorta |
3 Cardiac cells | 1; Automaticity (initiates the impulse) 2; Conductivity (passes the impulse along) 3; Contractility ( reacts to the impulse) |
When a cardiac cell is resting it is | Polarised - resting |
When an electrical impulse is recieved it is | Depolarised - action |
Once the pathway has been depolarised it is | REpolarised - REcovery |
What is the order of primary cardiac conduction | SA nodes - VA nodes - Bundle of His (right and left) - Purkinje fibers |
P wave | After the SA node fires spontaneously, a wave of depolarization spreads through the Atria, creating a wave. |
What happens immediately after the P wave | There is a pause (as the impulse passes through the AV node) a straight line on the ECG |
In the QRS complex - any wave above the baseline is called a "__" wave | R wave |
A negative deflection following an R wave is an "__" wave | S wave |