Anatomical features of the breast bone of the Baikal nerpa

The breast bone forms the lower limits of chest, where, under influence inspiratory muscles, it moves down, and expiratory muscles - up. During land travel, kinetic energy is absorbed through bone. In available literature, there are descriptions in some mammals, however, Baikal seal, data require additional clarification. material was sternum from seals aged 6 months to 11 years (n=7). course study, specific features morphology seal age aspect were established. particular, formed handle, seven body segments, xiphoid process well-defined cartilages (the handle process). value length increases 1.4 times with 47.7 ± 1.87 cm. Features cartilaginous structures sternum, create mobility its cranial part, maximum strength between 7th segment process. cartilage at base expanded, undergoes ossification. kumutkans, 68.4±2.33 mm long, 13.1±1.09 wide 5.8±0.13 thick; by mature seals, these values increased 1.6 times, 1.8 1.9 respectively. segments thoracic have a prismatic shape rounded edges, on surfaces 3rd-4 th ends 1 st (2nd) caudal ends, presence pronounced median furrow noted. On process, two pits protruding dorsally ridge stand out, has pedicle, which caudally turns into plate.