Final answer:
The cardiac intrinsic conduction system consists of the SA node, internodal pathways, AV node, AV bundle, and Purkinje fibers. It autonomously generates and conducts action potentials, coordinating the heart rate and pumping of blood.
Step-by-step explanation:
Cardiac Intrinsic Conduction System
The cardiac intrinsic conduction system is a network of nodal tissue and conducting cells in the heart that establish the heartbeat and coordinate the contraction of cardiac muscle. There are several key components to this system:
- The Sinoatrial (SA) node, often termed the pacemaker of the heart, generates electrical impulses spontaneously, thereby setting the pace for the heart rate.
- These impulses then move through internodal pathways including anterior, middle, and posterior to the Atrioventricular (AV) node.
- There is then a key delay at the AV node, approximately 100 milliseconds, which allows the atria to complete their contraction and pump blood into the ventricles.
- After the delay, the impulse continues into the Atrioventricular (AV) bundle (Bundle of His), which branches into the right and left bundle branches.
- Finally, impulses travel to the Purkinje fibers, triggering the muscles to contract and effectively pump blood through the heart and to the rest of the body.
These components work synchronously to regulate the heart's rhythmic contractions and are critical for the efficient pumping of blood.
The unique feature of this system is its ability to generate and conduct action potentials autonomously, without neural input, although heart rate and force can be influenced by the nervous system.