can you tell in a short sentence how is the structure of this respiratory organ in birds?
The lungs of birds contain millions of tiny parallel passages called parabronchi. Small sacs called "atria" radiate from the walls of the tiny passages; these, like the alveoli in other lungs, are the site of gas exchange by simple diffusion.
Lung
The lungs of birds contain millions of tiny parallel passages called parabronchi. Small sacs called "atria" radiate from the walls of the tiny passages; these, like the alveoli in other lungs, are the site of gas exchange by simple diffusion. 
where are the human lungs located in the body Near the backbone on either side of the heart. what distinguishes the right lung from the left lung in humans? The right lung is bigger than the left, which shares space in the chest with the heart. name some tissues which make up that organ. UNANSWERABLE what is the function of this respiratory organ? The major function of the lungs is gas exchange between the lungs and the blood. The alveolar and pulmonary capillary gases equilibrate across the thin blood–air barrier. from where does this organ get its blood supply? The lungs have a dual blood supply provided by a bronchial and a pulmonary circulation. The bronchial circulation supplies oxygenated blood to the airways of the lungs, through the bronchial arteries that leave the aorta. what happens to the organ if there is a deficiency in vitamin a? This can disrupt the normal physiology of the lung and predispose to respiratory diseases.
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Lung [SEP] Birds
The lungs of birds contain millions of tiny parallel passages called parabronchi. Small sacs called "atria" radiate from the walls of the tiny passages; these, like the alveoli in other lungs, are the site of gas exchange by simple diffusion. The blood flow around the parabronchi and their atria forms a cross-current process of gas exchange (see diagram on the right). The air sacs, which hold air, do not contribute much to gas exchange, despite being thin-walled, as they are poorly vascularised. The air sacs expand and contract due to changes in the volume in the thorax and abdomen. This volume change is caused by the movement of the sternum and ribs and this movement is often synchronised with movement of the flight muscles.