A set of structures in the cardiac muscle which create and transmit an electrical impulse, forcing the atria and ventricles to contract.
2 of 13
What is myogenic?
The capacity of the heart to generate its own electrical impulse, which causes the cardiac muscle to contract.
3 of 13
What is the sino-atrial (SA) node?
Located in the right atrial wall, the SA node generates the electrical impulse and fires it through the atrial walls, causing them to contract. This determines the heart rate.
4 of 13
What is the atrio-ventricular (AV) node?
The AV node collects the impulse and delays it for 0.1 seconds to allow the atria to finish contracting.
5 of 13
What is the Bundle of His?
Located in the septum of the heart, the Bundle of His splits the impulse in two, ready to be distributed through each separate ventricle.
6 of 13
What is the bundle branches?
These carry the impulse to the base of the each ventricle.
7 of 13
What is the purkyne fibres?
These distribute the impulse through the ventricle walls, causing them to contract.
8 of 13
What is the cardiac cycle?
The process of the cardiac muscle contraction and the movement of blood through its chambers.
9 of 13
What is diastole?
The atria and ventricles relax, drawing blood into the atria. The pressure in the atria then increases, opening the AV valves and blood passively enters the ventricle. SL valves are closed to prevent blood from leaving the heart.
10 of 13
What is atrial systole?
The atria contract, forcing remaining blood into the ventricles.
11 of 13
What is ventricular systole?
The ventricles contract, increasing the pressure closing the AV valves to prevent backflow into the atria. The SL valves are forced open as blood is ejected from the ventricles into the aorta and pulmonary artery.
12 of 13
How is the conduction system and cardiac cycle related?
Diastole - No electrical impulse Atrial systole - SA node fires impulse. Ventricular systole - The purkyne fibres distributes the impulse through the ventricle walls.
13 of 13
Other cards in this set
Card 2
Front
What is the conduction system?
Back
A set of structures in the cardiac muscle which create and transmit an electrical impulse, forcing the atria and ventricles to contract.
Comments
No comments have yet been made