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AS PE Heart
Conduction system and cardiac cycle
Question | Answer |
---|---|
What is artrial diastole | First part of cardiac cycle heart relaxes atria fill with blood |
What is ventricular diastole | Second part of cardiac cycle rising pressure due to filling with blood in the atria causes the AV valves to open and the ventricles to fill with blood |
What is artrial systole | Third part of cardiac cycle atria contract, forcing blood into the ventricles |
What is ventricular systole | Fourth part of the cardiac cycle ventricles contract increasing pressure in the ventricles and forcing blood into the aorta and pulmonary artery |
What does the SA node do? | emits an impulse |
What causes the artria to contract? | SA node emits impulse which travels across the artria causing them to contract |
What does the AV node do? | This picks up the impulse sent by the SA node and delays it before sending it on. |
What does the bundle of His do? | They transmit the impulse from the AV node down the septum to the bottom of the heart |
What is the role of the purkinje fibres? | These transmit the impulse across the ventricls causing them to contract |