Sacs that communicate with the respiratory, air-filled membranous system in birds and primates.
- avian a. s. — there are eight air sacs in the chicken: an unpaired cervical, an unpaired clavicular, a pair of cranial thoracic, a pair of caudal thoracic and a pair of abdominal sacs. They connect with the lungs through ostia along the ventrolateral borders of the lungs. The connections are to large and small bronchi. The sacs are also connected to and aerate the bones of the thoracic cage, including the vertebrae, the pelvis and the upper limb bones. Ducks have a similar pattern of air sacs to that of chickens. Turkeys have seven sacs: an unpaired cervicoclavicular sac, a pair of medial clavicular, a pair of cranial thoracic and a pair of abdominal sacs.
- a. s. disease — includes airsacculitis and air sac mite infestation (cytodites nudus).
- a. s. inflammation — see airsacculitis.
- a. s. mite — cytodites nudus.
- primate a. s. — laryngeal diverticula of variable size that reach extreme development in the gibbons.
