Abstract
The sinoatrial node of the rat is composed of loosely interwoven modified cardiac muscle cells, which are lined up in groups to form somewhat irregular layers or plates. A generous amount of atrial specific granules is found in their cytoplasm. Between the nodal cells there is a loose connective tissue containing numerous bundles of unit fibrils of collagen and unmyelinated nerve fibers. In the atrioventricular node the modified cardiac cells are larger than those of the sinoatrial node, and are arranged in small groups. They contain a large amount of glycogen. Unmyelinated nerve fibers are extremely numerous in the atrioventricular node and myelinated nerve fibers are also present.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
