Ecg And Rhythms

Question 1

What does the chemoreceptors control

Answer 1

Ph balance

Question 2

What are the 4 components of the hearts electrical system

Answer 2

SA node, the natural pacemaker
AV node, a ‘pause’ allows filling of chambers
Bundle of his, distribution node
Purkinje fibres, fibres that cause contraction

Question 3

What is an ECG

Answer 3

A non invasive trans-thoracic graphic produced by an electrocardiograph, it records the electrical activity of the heart over time and can be static or ambulatory

Question 4

What is depolarisation and repolarisation

Answer 4

Depolarisation- contraction of the heart
Repolarisation- preparation to contract

Question 5

What does the P wave represent

Answer 5

Depolarisation of the atria in response to SA node triggering
Arterial contraction forces blood into ventricles

Question 6

What does the PR interval represent

Answer 6

The delay of AV node to allow filling of ventricles

Question 7

What does the QRS complex represent

Answer 7

Depolarisation of the ventricles, triggered by signals from the AV node
Ventricular contraction pushes AV valves closed

Question 8

What does the ST segment represent

Answer 8

The beginning of ventricle repolarisation

Question 9

What does the T wave represent

Answer 9

Repolarisation of the ventricles, semilunar valves open and blood is ejected and the completion of a standard heartbeat

Question 10

What is the formula for cardiac output

Answer 10

Heart rate x stroke volume