[The anatomy of the heart of tortoises (Testudinidae)].

25 formalin-fixed hearts of different tortoise species (Testudinidae) underwent gross-anatomical examination. The aim of the study was to illustrate the specific anatomy of the heart of these species in comparison to the data available in the literature. The examined tortoises showed the well-known basic structure of a reptile heart with two atria and a ventricle composed of three interconnected chambers. The right atrium was consistently slightly larger than the left atrium. The atrioventricular (AV-) valves emerged as double-flap valves, whereby the lateral leaflets were only present in a rudimentary form. Neither papillary muscles nor chordae tendineae could be detected macroscopically. A vertical septum in order to subdivide the dorsal chambers was missing. However, the muscular ridge between Cavum venosum and Cavum pulmonale was well developed. The Cavum pulmonale represented itself as the smallest chamber respectively rather as a small passageway to the Truncus pulmonalis. Apart from two-parted aortic valves also multicuspidated valves of the Truncus pulmonalis could be visualized.