Question

answer the following questions below:

Draw a simple flow chart of the cardiac conduction system and explain the function of each component

.

Briefly explain the 3 major waves in the ECG record  in term of the electrical activity and the mechanical events.

Why does the QRS complex has greater signal than P wave?

What is the isoelectric line of the ECG?

Answer 1

>SUPERIOR SINOATRIAL NODE (SA NODEJ VENACAVA to PULMONARY HACEÑARSE) VEINS → AV NODE TPACE SETTER BICUSPID VALVE (MITRAT VALVĖ) 4 TRICUSPIDE VALVE HRV / lvl INFERIOR IVENACAVA

• From the SA node, impulse is released and travels on the walls of atrias and atrias contract. This is called as Atrial systole.

• When atrial systole happens:

1) Deoxygenated blood from Right atria enters into right ventrical through tricuspid valve.

2) Oxygenated blood enters from left atria enters into left ventricle through bicuspid valve.

• Then, one of the impulse comes in AV node and it gets activated. From the AV node arises right bundle of his and left bundle his.

• Once these bundle of his enters ventricle,they give rise to fibres that spread into ventricles called as purkinje fibre. Due to this the ventricles contract which is called as ventricular systole.

• When ventricular systole happens:

1) Deoxygenated blood from right ventricle enters into lungs.

2) Oxygenated blood enters into body.

• Then the relaxation of the muscles happens which is called joint diastole and when this happens:

1) Deoxygenated blood enters right atria through superior venacava,inferior venacava and coronary sinus.

2) Oxygenated blood enters Left atria through pulmonary vein.

• 1 systole+ 1 diastole = 1 heartbeat.

• The three major waves in the ECG Record in terms of electric activity and mechanical events are:

1) P Wave- it indicates atrial systole which is the contraction of atria beacuse the action potential is generated in SA node.

2) QRS Complex- It is the combination of Q, R and S waves and indicates ventricular systole . Ventricular systole is the contraction of the ventricles which happens because of action potential moving from AV node through bundle of his or purkinje fibres into ventricular muscles.

3) T Wave- It indicates the vetricular repolarisation in which the ventricles relax.

• The QRS Complex has greater signal than P Wave because ventricles has more muscles in comparison to atria.

• The isoelectric line of ECG appears when there is no contraction and relaxation.