ECG's & Cardiac Cycle

Question 1

What does a P wave represent?

Answer 1

Depolarisation/ Systole / Contraction

Atrial filling. SA node fires an electrical signal to the walls of the atria causing depolarisation / contraction.

Blood into atria

Question 2

What does the PQ Segment Represent?

Answer 2

Systole / Depolarisation/ Contraction

The time for the signal fired from the SA node to the AV node.

Blood into the ventricles.

Question 3

What occurs at the QRS?

Answer 3

Systole. Firing of the AV node.
Ventricular depolarisation. Semilunar valves open.

Signal spreads through ventricle walls causing contraction

Question 4

ST Segment

Answer 4

Systole / Contraction / Depolarisation

Ventricles contract and pump blood into pulmonary arteries and aorta.

Should be flat

Question 5

What does the T wave represent?

Answer 5

Ventricular repolarisation / diastole

Question 6

What is Diastole

Answer 6

Diastole is repolarisation. A period of relaxation of the heart muscle, accompanied by the filling of the chambers with blood.

Question 7

What is Systole

Answer 7

A period of depolarisation where the heart muscles contract and allow for blood to be pumped into relevant chambers etc.