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Cardiac Conduction
Steps of Cardiac Conduction chapter 14
Question | Answer |
---|---|
Step 1 CC | Normal cardiac impulses in the Sinoatrial SA node from its spot in the wall of the right atrium just below the opening of the superior vena cava |
Step 2 CC | An interatrial bundle of conducting fibers rapidly conducts the impulses to the left atrium, and both atria begin to contract |
Step 3 CC | The impulse travels along three internodal bundles to the atrioventricular AV node (located near the right AV valve at the lower end of the interatrial septum) The impulse dlows considerably to allow the atria time to contract and ventricles to fill with |
Step 4 CC | After passing through the AV node the impulse picks up speed. It then travels down the bundle of His, also called the atrioventricular AV branches. |
Step 5 CC | The AV bundle soon branches into right and left bundle branches |
Step 6 CC | Purkinje fibers conduct the impulses throughout the muscle of both ventricles causing them to contract almost simultaneously. |