EN
The aim of the research was to determine the morphological types of the aortic valve of domestic fowl. One hundred and six birds were used in the study (52 males and 54 females). Sections at various levels were made as well as corrosion preparations. Morphologically, two types of valves were distinguished: a tricuspid valve and a quadricuspid valve. The quadricuspid structure of the aortic valve is very rare in the animal world, whereas in the humans, it is most frequently connected with existing inborn defects of great vessels.