Cardiac Conduction System Flashcards
(17 cards)
What is the cardiac conduction system?
> A network of nodes, cells, and signals that control your heartbeat
What are the 3 layers of the heart?
1) Pericardium (outer layer)
2) Myocardium (second layer)
3) Endocardium (inner layer)
What is the myocardium?
> Middle, muscle layer (thick and large)
Facilitates contraction and relaxation of the heart walls to receive and pump blood
A cardiac impulse is transmitted throughout - activating all muscle tissue (myogenic)
The septum is myocardial tissue which divides the heart into its double pump
What are the atria?
Top chambers of the heart - receive blood from the lungs and body
What are the ventricles?
Bottom chambers of the heart - pumps blood to lungs or body
What are the atrioventricular valves: (bicuspid and tricuspid)?
Control blood flow from the atria to ventricles
What are the semi-lunar valves: (Aortic and Pulmonary)?
Prevent back flow of blood into ventricles
What is the septum?
The muscular wall that separates the sides of the heart
What is the aorta?
Main artery of the system - transport oxygenated blood to the body
What is the venacava?
Main vein of the system - transports deoxygenated blood to the heart
What is the Pulmonary artery?
Specialised artery - carries deoxygenated blood from the right atrium to the lungs
What is the Pulmonary vein?
Specialised vein - carries oxygenated blood from the lungs to the left atrium
What is the Sinoatrial Node: (SA)?
Pacemaker of the heart, generates electrical impulses
What is the Atrioventricular Node: (AV)?
Distributes nerve signals from the SA node, delaying age contractions between the atria and ventricles
What is the Bundle of HIS?
Carries the electrical signals from the AV node to the septum, the walls of the heart, and the purkinjie fibres
What are the Purkinjie Fibres?
A network of fibres that receive conductive signals from the AV node, which then activates the ventricles causing them to contract and eject blood
What are the 5 steps of the Conduction system?
1) The cardiac impulse originates at the SA node
2) The impulse travels down the atrial myocardium to the AV node
3) The impulse spreads to the bundle of HIS
4) The bundle connects the AV node to the septum via purkinjie fibres
5) The purkinjie fibres are connected to cardiac muscle fibres - the ventricles contract (systole)
