Heart conducting system Flashcards
what is the heart conducting system?
The cardiac conduction system initiates and coordinates contraction of the atria and ventricles. Cardiac muscle can generate its own contractions (i.e., not driven by motor innervations as in other muscles) and can conduct it from muscle to muscle until the whole heart is involved.
What are cardiac conducting cells?
Cardiac conducting cells are specialized muscle cells that carry conductions to the heart muscle faster than normal cardiac muscle cells
What are the parts of the heart conducting system?
Sino atrial node (SA node) crista terminalis Atrioventricular (AV) node Atrioventricular bundle subendocardial plexus of conduction cells (Purkinje fibers)
Where does the impulses begin?
SA node
this is the cardiac pacemaker where the contractions are set
Where does the signal travel after SA node?
. A signal in at the SA node spreads across the atrial wall and causes the chamber to contract.
Where are the SA node cells?
. Cells are collected in the superior end of the crista terminalis at the junction of the SVC and right atrium
What causes the AV node to get excited?
after the atrial walls contract this cause the AV node to get excited
Where is the AV node located?
located near the opening of the coronary sinus, via the atrial muscle
What is the AV bundle?
continuation of the AV node
Where is the AV bundle located?
follows along the lower border of the interventricular septum (toward apex), then splits into right and left bundles.
What is the function of the AV bundles?
carry signals to their respective ventricles and make them contract
What are the Subendocardial plexus of conduction cells (Purkinje fibers)?
located in ventricular walls of the heart & conducted electrical signals that allows to contract in a coordinated fashion.
