What is the significance of atrio-ventricular node and atrio-ventricular bundle in the functioning of heart?
The atrio-ventricular node (AVN) is significant as it conducts the action potential to the ventricular side. It ensures that the electrical impulse initiated by the sino-atrial node is successfully transferred from the atria to the ventricles.
The atrio-ventricular bundle (AV bundle) continues from the AVN and transmits the action potential through the entire ventricular musculature. This transmission occurs via the bundle branches and Purkinje fibres, which causes the ventricular muscles to contract (ventricular systole). This coordinated contraction allows the ventricles to efficiently pump blood into the circulatory system.
Explanation
The answer is derived from the textbook context which states that the action potential is conducted to the ventricular side by the AVN and AV bundle. The AV bundle (along with Purkinje fibres) transmits this impulse through the ventricular musculature, causing ventricular contraction. This highlights the role of these structures in ensuring the sequential contraction of heart chambers (atria followed by ventricles).