Fibrous ring

The fibrous rings of the heart are specialized, dense connective tissue structures that form part of the cardiac fibrous skeleton. They are composed of collagen and elastic fibers and are concentrated at the base of the ventricular mass. These rings provide structural support and electrical insulation for the heart, particularly at the atrioventricular level, and serve as the anchoring sites for the leaflets of the right and left atrioventricular valves, and aortic and pulmonary valves.

The fibrous rings include the different valvular annuli and are continuous with other elements of the fibrous skeleton such as the fibrous trigones.