Comparative anatomical study of the tricuspid valve-complex in human, sheep, goat, cow and pig

Aims and objectives: Accurate functioning of the papillary muscles and their chordae is very essential to maintain good competence of the valves. Their dysfunction can lead to valvular incompetences. A comparative study of papillary muscles of ventricles of human, sheep, goat, cow and pig is done. Through this comparative anatomic approach, the morphology of the human tricuspid valve complex, its similarities and differences to those of the animal hearts studied becomes more apparent. Methods: The hearts were opened to view the interior of the ventricles. Diameter of the tricuspid valve was measured in all the hearts. The number of papillary muscles, their positions, length and thickness in man and other mammals were noted. The number of chordae tendineae attached to each papillary muscle and the cusps along with their attachment to different zones of the cusps were observed and counted. Results: The number and position of the papillary muscle was similar in all the specimens but the number of bellies of each papillary muscle varied. Length and thickness of the papillary muscles were more in cow and least in pig. Chordae tendineae number attached to the papillary muscle and to the cusp was more in pig and man. It was least in sheep and goat. Interpretation and Conclusion: The internal structure of the heart differs from species to species. Although some differences exist, the heart of pig appears very similar to man.