Final answer:
Sinus arrhythmia involves the sinoatrial node, internodal pathways, atrioventricular node, and other conduction system components, working together to coordinate the heart's rhythm, which naturally varies with breathing.
Step-by-step explanation:
The components of sinus arrhythmia include the sinoatrial (SA) node, the internodal pathways (anterior, middle, and posterior internodal), the atrioventricular (AV) node, the atrioventricular bundle, the right and left bundle branches, and the Purkinje fibers. The SA node initiates the sinus rhythm by generating electrical impulses that make the heart contract. This rhythm can experience natural fluctuations in response to breathing, influenced by the autonomic nervous system and endocrine hormones.
The conduction system ensures that the heart contracts in a coordinated manner, with impulses traveling from the atria to the ventricles.