Salim Salih Ali Al-khakani - Anatomy and Histology Department,
Eklas Abid Hamza Al-alwany - Anatomy and Histology Department
Hawraa H.Naji - Physiology, medicine and biochemistry Department
Hawraa M.Murad - Pathology and poultry disease Department College of Veterinary Medicine of Al Qasim Green University

Macroscopical and morphometric account of respiratory system in adult pigeons (Streptopelia decaocto), the number of pigeon which are used in this study ten healthy mature pigeon birds , which are collected from markets (AL-Hilla city), all birds transferred to the Al-Qasim green university ,veterinary anatomy laboratory , the birds were anesthetized and sacrificed by used intramuscular administration then the birds dissecting by fixed the birds on the dorsal recumbence and make incision from the neck to the pelvic region , then separate the respiratory system to record morphological measuring, . The trachea in pigeon birds appears as cylindrical flexible long tube made of complete circular cartilages rings, the mean weight of birds and respiratory system (179 .71± 0.05gm , 2.34±0.016gm ) also length of the body and respiratory system was (30.5±0.09cm ,10.8±0.15 cm),the length ,weight of trachea and number of its cartilage ring was (7.1±0.02 cm,0.25±1.2gm ,98.5± 3.1) while the length of right and left lung (1.6±0.05 ,2.1±0.035) for the more the weight of right and left lung (0.66±2.01,0.85±1.2 gm). Observe diameter of cartilage approximately unequal where the average of diameter at above region is ( 0.45± 1.1 cm) while at the middle region (0.35±0.3) and at lower region is ( 0.3± 0.0 cm). The number of ring cartilage that forming the right and left primary bronchi was (9.5±2.1,8.3±1.2) also the thickness of right and left lung (0.5±0.3,0.6±0.6 cm) .The weight of the respiratory system in birds is directly proportional to body weight and therefore there is no similarity between the morphometric study of birds

pigeon, respiratory system, birds ,trachea