2009. Evidence for bird-like air sacs in saurischian dinosaurs. Journal of Experimental Zoology 311A: 1-18. http://dx.doi.org/10.1002/jez.513Wedel, M. J.: Evidence for bird-like air sacs in saurischian di- nosaurs, J. Exp. Zool. A, 311, 1-18, 2009....
Due to the high metabolic rate required for flight, birds have a high oxygen demand. Development of an efficient respiratory system enabled the evolution of flight in birds. Birds ventilate their lungs by means of air sacs, structures unique to birds (and hence, perhaps dinosaurs, too). These...
Numerous avian traits and their precursory stages are evident in their theropod dinosaur ancestors and maintained to the bird lineage, as seen in their capacity for flight (such as the large stiff pennaceous flight feathers, air-sacs, three-digit forelimbs that developed into wings, pneumatic ...
Bird - Muscles, Organs, Flight: Birds have a complete separation between pulmonary and systemic circulation, hearts that are large for their body weight, lungs connected to nonvascular air sacs, and a digestive system adapted to high metabolism and fligh
Birds, on the contrary, have a complex weight-reducing system of air sacs and interconnecting tubes that make possible a more thorough bathing of the lung cells with fresh air. This is a very unique bird characteristic. To help supply heavy oxygen demands, the lungs are supplemented by a ser...
To begin with, the bird lung is invested with a series of hollow air channels, not dead-end alveoli. These air channels are connected to a network of thoracic air sacs. When the air sacs contract and relax in coordination, they force inspired air through the air channels in an almost con...
Birds have two sets of air sacs. One set has connections near the front of the lungs. The other set has connections to the back of the lungs. These are the anterior (cranial) air sacs, and the posterior (caudal) air sacs respectively. ...
In the house sparrow, the budgerigar and the violet-eared hummingbird the volumes of the lungs and air sacs are estimated from silicone casts. The quantitative composition of the lungs and of their compartments are measured on lung slices, the relative volumes of the parabronchi on histological ...
Second, a hemispherical-ended cylinder with uniform texture for most of the bird torso but with high density portions representing bird bones, as well as low density portions to represent the lungs and air sacs. Third, a bird model with a geometry more similar to real birds which included ...
Older birds, especially those who have lived in environments where there is second hand smoke may develop chronic problems with their air sacs and lungs. Some birds may also develop heart problems, in which case the bird may have 'fainting spells', difficulty breathing, and an enlarged abdomen...