The left and right fibrous trigone, fibrous skeleton of heart

What is the fibrous skeleton of the heart?

• A supporting scaffold for the myocardium

• An integrating assembly for cardiac anatomy

• Helps maintain the functional heart unit

What are the components of the fibrous skeleton?

• Mitral fibrous ring

• Tricuspid fibrous ring

What are the components of the fibrous skeleton

• Aortic fibrous ring

• Pulmonary fibrous ring

What are the components of the fibrous skeleton?

• Right fibrous trigone

• Left fibrous trigone

What are the additional structures of the fibrous skeleton?

• Membranous interventricular septum

• Subcommissural spaces

• Conal ligament

• Aortic curtain

• Tendon of Todaro

What are the components of the fibrous skeleton?

Right fibrous trigone
Left fibrous trigone

What are the additional structures of the fibrous skeleton?

Membranous interventricular septum
Subcommissural spaces
Conal ligament
Aortic curtain
Tendon of Todaro

Where is the right fibrous trigone located?

Between tricuspid and mitral orifices
At the base of the non-coronary aortic sinus

What is another name for the right fibrous trigone?

Central tendon of the heart

What are the three horns of the right fibrous trigone?

1️⃣ Posterior horn
2️⃣ Left anterior horn
3️⃣ Right anterior horn

What does the posterior horn of the right fibrous trigone do?

Extends over posterior interventricular septum
Forms fila coronaria → Contributes to mitral & tricuspid fibrous rings.

What does the left anterior horn of the right fibrous trigone do?

Participates in mitro-aortic continuity.

What does the right anterior horn of the right fibrous trigone do?

Lies over atrioventricular septum
May help form tricuspid ring.

Where is the left fibrous trigone located?

Between mitral and aortic valves
At the base of the left coronary sinus.

What are the three horns of the left fibrous trigone?

1️⃣ Right anterior horn
2️⃣ Left anterior horn
3️⃣ Posterior horn.

What does the right anterior horn of the left fibrous trigone do?

Enters conal ligament.

What does the left anterior horn of the left fibrous trigone do?

Helps form mitro-aortic continuity.

What does the posterior horn of the left fibrous trigone do?

Forms fila coronaria for mitral fibrous ring.

What is the first function of the fibrous skeleton?

Structural role → Supports atrial & ventricular myocardium.

What is the second function of the fibrous skeleton?

Electrical separation → Keeps atria and ventricles electrically isolated.

How does the fibrous skeleton help electrical conduction?

The AV bundle of His passes over the right fibrous trigone.

It descends on the posterior border of the membranous interventricular septum.

Then, it divides into right and left branches.