Summary
The SA node, AV node and Purkinje fibres coordinate heartbeat electrical signals seen on an ECG.
In depth
SA node (pacemaker, about 70 beats per minute) depolarises atria; delay at AV node lets ventricles fill; bundle of His and Purkinje fibres rapidly spread excitation. ECG: P wave (atrial depolarisation), QRS complex (ventricular depolarisation) and T wave (repolarisation).
The AV delay lets ventricles fill. Autonomic input adjusts rate. Arrhythmias arise from conduction faults.
Key idea: electrical activity precedes mechanical contraction.
Frequently asked questions
What is Cardiac Conduction System?
The SA node, AV node and Purkinje fibres coordinate heartbeat electrical signals seen on an ECG.
Which area of biology covers Cardiac Conduction System, and how advanced is it?
Cardiac Conduction System is one of the 51 topics in Human Physiology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Cardiac Cycle, Frank-Starling Law, Muscular System.
Can you give an example of Cardiac Conduction System?
Artificial pacemakers substitute for a failing SA node.
What should I learn before Cardiac Conduction System?
Work through the Beginner topics in Human Physiology first, such as Homeostasis, Tissues and Organs, Skeletal System, then return to Cardiac Conduction System. Advanced topics assume the Intermediate vocabulary.
What topics are related to Cardiac Conduction System?
The closest topics to Cardiac Conduction System are Cardiac Cycle, Frank-Starling Law, Muscular System, Digestive System. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Cardiac Conduction System?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cardiac Conduction System. To practise the whole of Human Physiology, use the Human Physiology quiz.
How is Cardiac Conduction System different from Cardiac Cycle?
Cardiac Conduction System: The SA node, AV node and Purkinje fibres coordinate heartbeat electrical signals seen on an ECG. Cardiac Cycle: The sequence of atrial and ventricular contraction (systole) and relaxation (diastole) in each heartbeat. Read both side by side and note what each one explains.
How should I study Cardiac Conduction System step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Cardiac Cycle and explain the difference aloud. Finally, take the Human Physiology quiz and come back to this page for any question you miss.