It is not a true skeleton, but it does provide structure and support for the heart, as well as isolating the atria from the ventricles. This allows the AV node and AV bundle to delay the wave of depolarisation such that the atria can contract and assist in ventricular filling before the ventricles themselves depolarise and contract (the AV bundle is the only part of the conduction system that passes from the atria to the ventricles in a normal heart). It also allows the valves (bicuspid, tricuspid, semilunar) to keep open by giving them structural support[WP]

http://upload.wikimedia.org/wikipedia/commons/5/50/Gray495.png

trigona fibrosa, trigonum fibrosum dextrum cordis, anulus fibrosus dexter cordis, anulus fibrosus sinister cordis, trigonum fibrosum sinistrum cordis

uberon

UBERON:0004292

Fibrous skeleton of heart

• cardiac skeleton development

• wall of heart
• atrioventricular valve