Unit 2: Week 3

Question 1

What is the cardiac cycle?

Answer 1

P, QRS complex, T

Question 2

What happens during the P wave and the PR interval?

Answer 2

The sinoatrial node sends an impulse to depolarise the atria.

The PR interval with where the impulse is sent through the atrioventricular node and there is a delay to allow the blood to pass into the ventricles and complete depolarisation of the atria

Question 3

What happens during the QRS complex?

Answer 3

The ventricles are depolarised via the bundle of his in the intraventricular septum and through the pakinji fibres. They are rapidly conducting fibres so both vent contract simultaneously.

The R wave is higher than the P wave as the ventricles are larger. The artia are repolarised during this wave but it has a much lower amplitude so there is no visible wave.

Question 4

What happens during the ST interval?

Answer 4

Is the time between vent depolarisation and repolarisation

Question 5

What happens during the T wave?

Answer 5

The vent repolarise

Question 6

What is the R-R interval?

Answer 6

The R-R intervals are the time between heart beats QRS complex where blood is pumped out of the body.