ABSTRACT
Today, with emphasis on the mechanical heart and heart transplantation from one human to another and one species to another, a knowledge of the anatomy of the bird's heart could contribute to these accomplishments. Eight male adult ostriches were used to study the heart macroscopically. This study revealed that the ostrich heart has some different features from the other birds, In the ostrich, fibrous pericardium as sternopericardial ligament attaches along the thoracic surface of the sternum. The central edge of muscular valve hangs down into the right ventricle and gives attachment to its rough parietal wall by a thick muscular stalk. The left and right pulmonary veins enter the left atrium independently and their openings were completely separated from each other by a septum. In the heart of the ostrich, the moderator bands were found in both the right and left ventricles in different locations. The right ventricle presents one tendinous moderator band near the base of the ventricle that extends from septum to the muscular valve. Also the moderator bands as tendinous thread like or flat sheet are usually present at about apex of the right ventricle that extends from septum to the parietal wall. In the left ventricle, there were some tendinous moderator bands close to the apex that extends from septum to the parietal wall and between trabeculae carneae of the parietal wall