View source for Cardiac wall arrangement, cardiac skeleton, chambers

=== '''Cardiac Skeleton''' ===
The '''cardiac skeleton''', also known as the fibrous skeleton of the heart, is a dense, fibrous connective tissue structure located between the atria and ventricles. It consists of four fibrous rings (anuli fibrosi) and the membranous portions of the septa of the heart.

# '''Fibrous Rings''': These rings encircle the orifices of the heart valves, providing structural support and attachment points for the valve leaflets. The rings include the left atrioventricular (mitral) ring, right atrioventricular (tricuspid) ring, pulmonary ring, and aortic ring.
# '''Trigones''': The right and left fibrous trigones are interconnections between the fibrous rings and are the strongest parts of the cardiac skeleton.
# '''Functions''': The cardiac skeleton serves several functions:
#* Separates the atria from the ventricles.
#* Maintains the valve orifices open.
#* Provides attachment points for valve leaflets and cusps.
#* Acts as an electrical insulator between the atria and ventricles.
#* Provides a framework for the attachment of myocardial fibers.