Corpus: Cardiac skeleton

The cardiac skeleton is a supporting structure in the myocardium of the heart consisting of connective tissue, cartilage and bone. It varies in strength from species to species.

The cardiac skeleton is located in the border area between the aorta or pulmonary trunk and the heart and between the atrial and ventricular muscles.

It consists of tendon tissue, cartilage and bone substance. The part that lies in the immediate vicinity of the ostium aorticum and thus in the centre of the cardiac valve plane prevents disruptive changes in the shape of the ostium during cardiac action. At the same time, it serves the ventricular musculature both as a point of origin and attachment.

The cardiac skeleton ensures that the heart functions normally.

Components[Bearbeiten]

The cardiac skeleton essentially consists of four individual rings, which are labelled differently depending on their location:

• Anulus fibrosi arteriosi, consisting of:
  • Anulus trunci pulmonalis (pulmonary ring around the pulmonary valve)
  • Anulus aortae (aortic ring around the aortic valve)
• Anuli fibrosi atrioventriculares, consisting of:
  • Anulus fibrosus dexter (right fibrous ring around the tricuspid valve)
  • Anulus fibrosus sinister (left fibrous ring around the bicuspid valve)

Anuli fibrosi arteriosi[Bearbeiten]

The anuli fibrosi arteriosi are rings of connective tissue that are not very resistant and are inserted between the aorta or the pulmonary trunk on the one hand and the two ostia of the ventricles on the other. As ring-shaped border structures, they are each composed of three arches with their convexity pointing towards the heart, which are connected to each other via their protruding, neighbouring legs.

Anuli fibrosi atrioventriculares[Bearbeiten]

The anuli fibrosi atrioventricularis behave similarly to the anuli fibrosi arteriosi. They resemble them both in their formation and in their shape. In their course they surround the atrioventricular openings and consist of a connective tissue fibre network that merges into the interstitium of the atrial and ventricular musculature. It should be noted that the rings are not in direct contact with the muscle fibres.

The anuli fibrosi atrioventriculares serve both the morphological and functional separation of the atrial and ventricular musculature. In this way, they ensure uninterrupted coordination of atrial and ventricular activity.

Horse[Bearbeiten]

In the horse, the cardiac skeleton consists of two sinewy layers that are completely independent of the anuli fibrosi. It is divided into a trigonum septale, trigonum ventriculare sinistrum and a trigonum ventriculare dextrum. The sinewy parts of the cardiac skeleton are supplemented by three cardiac cartilages: cartilago cordis septalis, cartilago cordis sinistra and cartilago cordis accessoria.

Bovine[Bearbeiten]

In cattle, the cardiac skeleton consists of two heart bones, a large, 50 to 60 mm long os cordis dextrum and a smaller os cordis sinistrum. In terms of position and function, both bones correspond to the trigona fibrosa of the horse and can therefore also be referred to as trigona ossea. As independent units, they belong to the conical area of the left ventricle and serve to maintain the shape of the ostium aorticum by stabilising it in the most favourable haemodynamic position. They also serve as the point of origin and attachment for the muscle fibres of the ventricular septum.

Dog[Bearbeiten]

The cardiac skeleton in the dog shows species-specific characteristics and consists of a trigonum cartilagineum dextrum and the cartilago cordis septalis.

Small ruminants[Bearbeiten]

In sheep and also in goats, the cardiac skeleton essentially consists of two cardiac bones, which are identical in shape to those of cattle.

Pig[Bearbeiten]

There are no scientific studies on the pig's cardiac skeleton. However, it is known that the pig has a cardiac cartilage that serves as a supporting element, which - similar to small ruminants - can ossify at an advanced age.

• Nickel, Richard, August Schummer, Eugen Seiferle. Volume III: Circulatory system. Textbook of the anatomy of domestic animals. Parey, 2004.
• Salomon, Franz-Viktor, Geyer, Hans, Uwe Gille. Anatomy for veterinary medicine. Enke-Verlag, 2005.