Air sacs are present in

Air sacs are present in poultry. Poultry, such as chickens, have a unique respiratory system that includes not only lungs but also air sacs. These air sacs are connected to the lungs and extend throughout the body cavity, allowing for efficient gas exchange and respiratory function. Air moves through the lungs and air sacs in a continuous, one-way flow, which helps birds to obtain oxygen and remove carbon dioxide more effectively than other animals with a less complex respiratory system. Therefore, air sacs are a key feature of the respiratory system of poultry, enabling them to have efficient gas exchange and support their high metabolic rate.