Skip to main content

Unfortunately we don't fully support your browser. If you have the option to, please upgrade to a newer version or use Mozilla Firefox, Microsoft Edge, Google Chrome, or Safari 14 or newer. If you are unable to, and need support, please send us your feedback.

Publish with us
Left Fibrous Ring
Cardiovascular System

Left Fibrous Ring

Anulus fibrosus sinister

Read more


The left fibrous ring consists of a dense connective tissue surrounding the left atrioventricular orifice. It forms part of the left atrioventricular valve.

Using the term anulus is somewhat problematic as they’re not annular in shape and are often discontinuous.

Complete Anatomy
The world's most advanced 3D anatomy platform
Try it for Free

Key Features/Anatomical Relations

The left fibrous ring provides the attachment point for the three left atrioventricular valve leaflets that sit at the junction between the left atrium and ventricle.

The left fibrous ring is connected to the aortic ring by the left fibrous trigone.


The collagen of the fibrous ring helps to separate electrical activities between the chambers by insulating the propagation of electrical impulses during a heartbeat. The left fibrous ring provides structural support and thus competency to the left atrioventricular valve and prevents its over distension. It also provides a direct attachment for cardiac muscle.

List of Clinical Correlates

- Mitral regurgitation

Complete Anatomy

The world's most advanced 3D anatomy platform

Complete Anatomy