Septomarginal trabecula and anterior papillary muscle in primate hearts: developmental issues

The septomarginal trabecula is present in all human hearts as well as in the hearts of other primates. It usually connects the interventricular septum with the anterior papillary muscle, although there are many variations in how this is achieved. The object of the analyses was to estimate the bilateral topography of the septomarginal trabecula and the anterior papillary muscle in the context of the ontogeny and phylogeny of primates. A total of 138 hearts were examined from number of different non-human primates. The presence of the septomarginal trabecula was confirmed in 94.9% of cases, although not in the hearts of Lemur varius. Four configurations could be distinguished by defining the location of the septomarginal trabecula and its relation to the anterior papillary muscle.For the hearts of the Strepsirrhini and the majority of Platyrrhini neither structure was related, whereas in all examined representatives of Homino idea they had fused and created morphologically varying forms. On the basis of these results,a concept was developed for the sequence of changes which the topography of the septomarginal trabecula and the anterior papillary muscle undergo during ontogeny and phylogeny.