Conduction system of the heart

Question 1

What system involves initiating electrical impulses & conducting them thru the myocardium to cause the heart to contract & then relax (cardiac cycle)

Answer 1

cardiac conduction system

Question 2

The myocardium consists of two sorts of muscle cells - one starts with “c”?

Answer 2

contractile cells - responsible for contracting & relaxing the myocardium

Question 3

The myocardium consists of two sorts of muscle cells - one starts with “a”?

Answer 3

autorhythmic cells - generate electrical impulses which activate the contractile cells.

Question 4

which cells are responsible for contracting & relaxing the myocardium?

Answer 4

contractile cells

Question 5

In the myocardium - which cells generate electrical impulses which activate the contractile cells?

Answer 5

autorhythmic cells - these cells have the characteristics of both muscle & nervous tissue.

Question 6

What is found in each component of the conduction system?

Answer 6

autorhythmic cells

Question 7

What is called the heart’s natural pacemaker?

Answer 7

sinoatrial node (SA)

Question 8

The sinoatrial node is located where?

Answer 8

in the top of the right atrium

Question 9

the electrical signal starts in which node?

Answer 9

sinoatrial node - moving from cell to cell making the atria contract, pushing blood into the ventricles.

Question 10

The electrical impulses from the atria arrive at the (which node)?

Answer 10

atrioventricular node (AV)

Question 11

Where is the atrioventricular node located?

Answer 11

in the interatrial septum just above the tricuspid valve.

Question 12

The signal from the atrioventricular node pauses for a 10th of a second whilst the atria contracts & ventricles fill with blood then moves quickly to the?

Answer 12

atrioventricular bundle or bundle of his.

Question 13

The atrioventricular bundle runs thru the interventricular septum then branches into the both the ventricles- these branches are called?

Answer 13

the right bundle branch & the left bundle branch

Question 14

The right & left bundle branches (which are in the ventricles) lead to what?

Answer 14

conduction myofibres or purkinje fibres

Question 15

What are specialised cardiac cells (cardiocytes) which fan out in the ventricular walls & cause them to contract from the bottom of the ventricle & pump blood up into the arteries?

Answer 15

conduction myofibres or purkinje fibres

Question 16

The …… ….. generated by the heart can be detected thru out the body.

Answer 16

electrical impulses

Question 17

Electrodes placed on the chest, arms & legs can pick up the impulses & transmit them to an ?

Answer 17

electrocardiograph machine

Question 18

The graphic recording of the heart’s electrical activity is an?

Answer 18

electrocardiogram (ECG)

Question 19

3 waves appear on the ECG with each heartbeat - what is the contraction (or depolarisation) of the atria called?

Answer 19

P wave

Question 20

3 waves appear on the ECG with each heartbeat - what is the contraction (or depolarisation) of the ventricles & relaxation (or repolarisation) of the atria called?

Answer 20

QRS complex

Question 21

3 waves appear on the ECG with each heartbeat - what is the relaxation (or repolarisatiion) of the ventricles called?

Answer 21

T wave