The Cardiac Cycle Flashcards
What is Atrial Systole?
The contraction of the right and left atria
atria - plural for atrium
What is ventricular systole?
Contraction of the ventricles
What is complete cardiac diastole?
Relaxation of the atria and ventricles
What does the Sinoatrial (SA) node do?
Initiates heartbeat
What does the Atrioventricular (AV) node do?
sends signal to ventricles after a short delay
What do purkinje fibres do?
conduct impulse up the ventricle walls causing contraction
Where is the SA node situated?
in the upper wall of the right atrium
The SA node is known as the “pacemaker” of the heart
and is responsible for setting the rhythm of the heart. It ensures both atria contract simultaneously
Where is the AV node situated?
at the bottom right of the atrium
What is the role of the AV node?
Delaying the electrical impulses it receives from the SA node
What is an ECG?
A test which records the electrical signals in your heart
What do waves on an ECG trace tell us what is happening in the heart?
the waves represent the electrical activity of the heart
Why does the AV node delay the impulses it receives from the SA node?
This delay allows time for blood to empty out of the atria and into the ventricles
