Some features of the morphology of the heart (nasua nasua)

Abstract

Nasua nasua is a representative of the forests of South America, and is also kept as a zoo animal. The animals have a pronounced mobile and long nose, a fluffy long tail, as a means of signaling; strong claws on the pectoral limbs, which serve not only to move through trees, but also to get food. Currently, there are isolated works on the morphology of the abdominal aorta of this type, but no features of the morphology of the heart have been found, which was the purpose of our study. The material was preserved in a 10% formalin solution of the heart, taken in different years from sexually mature noses received from the Irkutsk Zoo Gallery and the Siberian Zoo of Irkutsk. Classical methods of morphological research were used in the work: fine dissection, morphometry of the heart and its structures, description, sketches and photographing. According to the results of the studies, it was found that the average value of the absolute mass of the heart was 18.2 ± 0.33 g, has an ellipsoid shape, and the ratio of the thickness of the ventricles is at the level of 1:2.8. The internal structure of the right atrium is built of five scallop muscles of the 1st order and nine of the 2nd order, and four scallop muscles of the 1st order and eight of the second order participate in the relief of the left atrium. The shape of the auricle at the right atrium of the heart is 1.5 times greater than the value of the left atrium. In the left ventricle of the heart there are three papillary muscles (cranial and two caudal) with 21-24 tendon strings, and in the right ventricle there are six papillary muscles that carry up to 31 tendon strings on their surface. The septomarginal trabecula connects the parietal pedicle of the accessory and the base of the large papillary muscle.