Nodal And Junctional Tissue Of The Heart Flashcards
What is the sino-atrial node?
Normally, it is the pacemaker of the heart
Why is the SAN the pacemaker of the heart?
Because it beats at the highest rhythm 90-110 beats/min
What are the two types of nodal tissue?
Sino-atrial node
Atrio-ventricular node
Where is SAN located?
In the wall of the right atrium near the opening of the superior vena cava
Where is the AVN located?
Septal wall of the right atrium
Can AVN initiate cardiac impulses?
Yes, but at slower rate 40 -60 beats/min
Where is the impulse from SAN delayed
In AVN before passing from atria into ventricles
Why is there need of a delay?
To allow enough time for the atria to empty their contents into ventricles before ventricular contraction begins
What is junctional tissue?
This tissue transmits action potentials from one part of the heart to the other
What does junctional tissue include?
The inter-nodal pathways
The a-v bundle ( bundle of his)
The left and right bundles
What are the left and right bundles?
Very large fibers that conduct APs from the a-v bundle to all parts of the ventricles
How does the cardiac impulse spread through the heart?
