cardiac conduction system Flashcards
what is the cardiac conduction system?
a group of cells located in the wall of the heart
what does the cardiac conduction system do?
sends electrical impulses to the cardiac muscle, causing it to contract
where does blood flow in the heart?
in through the atria and out through the ventricles
the heart is described as myogenic.
What does myogenic mean?
the capacity of the heart to generate its own impulses
what is the sinoatrial node? (SA node)
a small mass of cardiac muscle found in the wall of the right atrium that generates the heartbeat, commonly called the pacemaker
what happens in the SA node?
an electrical signal that starts the heart beat
where does the impulse from the SAN pass through?
the atrioventricular node
what does the atrioventricular node do? (AV node)
relays the impulse between the upper and lower sections of the heart
delays transmission of the cardiac impulse for 0.1 seconds to allow atria to fully contract before ventricular systole begins
what is ventricular systole?
when the heart contracts
where does the electrical impulse then travel to?
through the bundle of His
what is the bundle of His?
a collection of heart muscle cells that transmit electrical impulses from the AVN via the bundle branches to the ventricles
where is the bundle of His located?
in the septum, separating the two ventricles
what does the bundle of His do?
branches out into two bundle branches and then moves into smaller branches called purkinje fibres
what are purkinje fibres?
muscle fibres that conduct impulses in the walls of the ventricles
They spread through the ventricles causing them to contract
