STRUCTURE-FUNCTION RELATIONSHIPS OF THE SINOATRIAL NODE

Publisher Website
Google Scholar
Abstract
The sinoatrial node, the pacemaker of the heart, is a structurally and functionally complex and heterogeneous structure. Histology, immunohistochemistry, electrophysiology and mathematical modeling of the sinoatrial node are reviewed to reveal the structure-function relationships of the sinoatrial node. It is argued that contact between the sinoatrial node and surrounding atrial muscle is limited to permit driving of the atrial muscle by the sinoatrial node but not suppression of the sinoatrial node by the atrial muscle (which is more hyperpolarized). It is argued that a protective conduction block zone on one side of the sinoatrial node is the result of a lack of myocytes. Finally, it is argued that the cellular organization of the sinoatrial node is best described by the gradient model.