Influence of morphological and functional features of the chest wall muscles structure on the biomechanics of the chest in chicken and Italian goose

The aim of the research is to study the structural features of the respiratory system and chest muscles, involved in the act of inhalation and exhalation in the Hisex Brown cross chickens and the Italian goose at 160 days of age. The studies were carried out at the Department of Anatomy, Histology, Physiology and Pathological Anatomy. To study the structures of the lungs, muscles of the chest wall and air sacs, the method of conventional and thin dissection was used. According to the results of the study, we note that the respiratory system is represented by lungs with complex bronchi and air sacs that lie inside the chest, formed by thoracic vertebrae in the amount of 7 (in chickens) and 10 (in geese), ribs and sternum. The chest of birds is divided into dorsal (static and supporting) and ventral (dynamic and respiratory) sections. The respiratory system of birds includes cranial - inhalatory (interclavicular, cervical, cranial thoracic) and posterior - expiratory (caudal chest, abdominal) air sacs connected with the bronchi and lungs with the help of conducting airways. The air sacs are thin-walled, connective-tissue, have a different volume of filling, being a continuation of the terminal sections of the bronchi, located outside the lungs. The cranial group (expirators) of the air sacs is located in the craniodorsal region of the thoracic cavity; their volume in chicken is 23.6% and in goose - 30.7%. The caudal group (inspirators) lies in the caudodorsal section of the abdominal cavity and occupies 76% of the total volume of all air sacs in chicken and 69.3% in goose. In the studied bird species, the caudal air sacs are 40% larger than the cranial ones.