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

Farlex Partner Medical Dictionary © Farlex 2012

air sac

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.

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.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

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References in periodicals archive

A suitable air sac sample was not detected for examination.

Diplotriaena--An Air Sac Nematode Found in a New Holland Honeyeater (Phylidonyris novaehollandiae)

The abdominal air sac (A) thickened by friable tan to grey exudate.

Aspergillus Section Nigri-Associated Calcium Oxalate Crystals in an Eurasian Eagle Owl (Bubo bubo)

([dagger]) Three juvenile chickens and turkeys inoculated through the air sac were killed on days 0, 2, 4, 6, 8, and 14 posinoculation, and left and right lung lobes were removed for analysis by real-time reverse transcription-PCR.

Limited susceptibility of chickens, turkeys, and mice to pandemic (H1N1) 2009 virus

Molecular characterization: Polymerase chain reaction (PCR) was used for detection of MG in organs (trachea, lungs and air sacs) of infected birds as described by Santha et al.

IDENTIFICATION OF MYCOPLASMA GALLISEPTICUM BY POLYMERASE CHAIN REACTION AND CONVENTIONAL DIAGNOSTICS FROM WHITE LEGHORN LAYER FLOCKS

(17,18) The intestinal peritoneal cavity contains the urogenital organs, gastrointestinal tract, spleen, and left and right abdominal air sacs. (17,18) The only connection between the different coelomic cavities occurs between the intestinal peritoneal cavity and the left dorsal hepatic cavity.

Lateral Body Wall Herniation Involving the Oviduct in Two Psittacine Birds

Some of the models contained an air sac, the Daily Mail reported.

'Doh' may have been one of man's first words!

The lung-on-a-chip microdevice takes a new approach to tissue engineering by placing two layers of living tissues-the lining of the lung's air sacs and the blood vessels that surround them-across a porous, flexible boundary.

Now, living, breathing human lung-on-a-chip

The right and left testes were enlarged, approximately 3 X 2.5 X 1.5 cm, and soft with multifocal tan ridges compressing the tunica albuginea and associated abdominal air sacs. On cut sections, the testicular parenchyma moderately bulged and occasional irregular soft necrotic areas were present within the parenchyma (Fig 2A).

Bilateral Malignant Seminoma With Ventricular Metastasis in a Bald Eagle (Haliaeetus leucoceplialus)

Tracheal endoscopy revealed an obstruction of approximately 90% of the tracheal lumen, in addition to mild suspected aspergillosis of the air sacs. Tracheal resection and anastomosis were performed, during which 1.5 cm of abnormal trachea was removed.

Tracheal Resection in a Secretary Bird (Sagittarius serpentarius) with Granulomatous, Foreign-body Induced Tracheitis

Marek's disease, or leucosis, may result in gonadal neoplasia, especially in chickens, leading to massive enlargement of the reproductive organs and subsequent air sac compression.

Radiography and ultrasonography in the backyard poultry and waterfowl patient

A total of 20-30 nematodes, approximately 20-30 cm in length, were found in the coelomic cavity and in the thoracic and abdominal air sacs, which were diffusely opaque and thickened.

Serratospiculosis in captive peregrine falcons (Falco peregrinus) in Switzerland

Additionally, administration of amphotericin B, as a nebulization agent, often is recommended, especially for cases with significant air sac disease.

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