RESUMO
The morphology and position of the papillary muscle of the arterial conus were studied in 50 human hearts of both sexes. In 40 hearts, the interventricular anterior and posterior arteries were filled with vinyl acetate to study the blood supply. the muscle lenght varied from 4 mm to 18 mm and the base of implantation was located between the anterobasal and posterobasal limbs of the septomarginal trabecula. The most frequent forms of muscle presentation were an attached conus (68 porcento of cases(, a free conus (10 porcento) and a double conus (6 porcento). the blood supply was derived from the first, second and third septal interventricular branches of the anterior interventricular artery in 75 porcento, 22.5 porcento and 2.5 porcento of the cases, respectively. Since the term "papillary muscle of the arterial conus"is not a standard anatomical term, and since "septal papillary muscle"does not clearly define the muscle position in the septal wall of the right ventricle, new terminology is required to accurately describe the septal papillary muscles of the right ventricle.