air sac

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al·ve·o·lar sac

1. terminal dilation of the alveolar ducts, which give rise to alveoli in the lung; a small air chamber in the pulmonary tissue from which the pulmonary alveoli project like bays and into which an alveolar duct opens; Synonym(s): sacculus alveolaris [TA]
2. in birds, air-containing extensions of bronchi that connect with bone cavities.
Synonym(s): air sac

air sac

n.
1. An air-filled space in the body of a bird that forms a connection between the lungs and bone cavities and aids in breathing and temperature regulation.
2. See alveolus.
3. A saclike, thin-walled enlargement in the trachea of an insect.
4. An inflatable pouch attached to the larynx in certain mammals, including the nonhuman great apes.
Air sacclick for a larger image
Fig. 18 Air sac . The air-sac system of a bird (left-side).

air sac

a thin-walled extension to the lungs, present in the thorax, abdomen and bones of birds. Air sacs also occur as diverticula (outgrowths) of the TRACHEA in insects, where, as in birds, they are important in respiration.
References in periodicals archive ?
Microscopically, the air sacs were thick, fibrotic, and edematous and had large areas of surface necrosis covered by extensive inflammatory detritus with the previously described fungal hyphae.
At postmortem examination, a massive dark red and green blood clot was identified extending from the left lung to the left posterior thoracic air sac and left abdominal air sac.
This prevents the air sacs fulfilling their vital function - taking in oxygen and expelling carbon dioxide - so you become breathless.
At necropsy, severe trematodiasis with associated airsacculitis was observed in the clavicular and thoracic air sacs of all 3 birds.
Lomas, who collaborated on the study at the Lung Immunobiochemical Research Laboratory in Birmingham, England, suggest these two drugs may increase the number of neutrophils drawn to the lungs, where they can release elastase, an enzyme that can damage the air sacs. Researchers know that lung tissue inflamed by tobacco smoke or other irritants attracts neutrophils circulating in the bloodstream, a process that can lead to emphysema.
The caudal thoracic and abdominal air sacs bilaterally appeared compressed against the coleomic wall.
Necropsy revealed the presence of granulomas in the air sacs and/or lungs in 4 of 5 falcons and in 4 of 5 pigeons in the high dosage group.
Apart from CVD, it damages the airways and the small air sacs (alveoli) in the lungs, leading to COPD chronic obstructive lung disease), emphysema, chronic bronchitis, and lung cancer.
Emphysema was measured from CT scans that identify holes in the small air sacs of the participants' lungs, and lung function tests, which measure the speed and amount of air breathed in and out.
It causes tiny clusters of air sacs at the end of breathing tubes in the lungs to become inflamed and fill with fluid.