Abstract

An ostrich heart has two atria and two ventricles making it similar to mammals, and a valve system similar to that of other birds. The anatomical and biometrical characteristics of the fibrous skeleton and left atrioventricular valve of the ostrich heart (Struthio camelus) are described, contributing to functional anatomical understanding of the ostrich. We dissected 30 hearts from ostriches aged between 12 and 15 months. The length and width of the cusps of the left atrioventricular valve were measured and any significant differences in measurements were identified. The left atrioventricular and aortic rings in the fibrous skeleton were studied, and three kinds of fibrous skeleton were identified. No fibrous ring was detected in the right atrioventricular valve or the pulmonary valve. The left atrioventricular valve is predominantly tricuspid, with a larger septal cusp. Variations in cusp length indicated three types for the left atrioventricular valve. This enabled us to define the morphological characteristics of the fibrous skeleton and the functional morphology of the left atrioventricular valve of the ostrich heart. © 2025, Universidad de la Frontera. All rights reserved.