![anatomy blueprint pro review anatomy blueprint pro review](https://i.pinimg.com/originals/10/7a/ad/107aad4db96016711c358f420844e2be.jpg)
![anatomy blueprint pro review anatomy blueprint pro review](https://cdn.shopify.com/s/files/1/1655/2447/products/BUNDLE-1-2_1200x1200.jpg)
The large mass-specific gas uptake by the avian respiratory system, at rest and especially during exercise, could be exploited as a sensitive monitor of air quality. We suggest that these differences can be productively exploited to further our understanding of the basic mechanisms of inhalant toxicology (gases and particulates). In this paper, we review the physiology of the avian respiratory system with attention to those mechanisms that may lead to significantly different results, relative to those in mammals, following exposure to toxic gases and airborne particulates. There are many distinct differences (morphologic, physiologic, and mechanical) between the bird's lung-air-sac respiratory system and the mammalian bronchoalveolar lung. Measurements have shown that in fishes and birds X values for CO2 and O2 are close to their optimum values. The enhanced efficacy of the counter-current and cross-current models occurs only inside a limited range of X values (not far from 1.0). Generally, the effectiveness of the models, in terms of extent of gas transfer for same conductance values, increases in the sequence, uniform pool → cross-current → counter-current. when diffusion limitation and distributional inhomogeneities are absent, partial pressures of respiratory gases in the external medium and blood leaving the gas exchange organ relative to those in the medium and blood entering it are shown to depend, in a specific manner for each model, on the medium-to-blood conductance ratio, (V̇, flow rate β, “capacitance coefficient” m refers to respiratory medium b, to blood). The performance limits of the following models for vertebrate gas exchange organs have been investigated in theory: (1) counter-current model, for fish gills, (2) cross-current model, for avian lungs, and (3) uniform pool model, for mammalian lungs. The effective exchange surface per volume unit is ten times larger than that of comparable mammalian lungs. Development of small air capillaries requires a constant lung volume. The tissue mantle of the parabronchi is made up of a meshwork of blood and air capillaries within which the gas exchange takes place. This “neopuimo ” is best developed in fowllike birds and song birds.
![anatomy blueprint pro review anatomy blueprint pro review](http://dcpaleo.org/wp-content/uploads/2015/02/6.1-Trigeminal-Nerve-Chart.jpg)
Systematically higher birds possess an additional connecting network of parabronchi between the primary bronchus and the posterior air sacs. This structure is the “paleopuimo”, found in all birds. The special manner of the origin of the ventro-, dorso- and latero-bronchi from the primary bronchus is responsible for the ventilation of the parabronchi which connect the total internal surfaces of the dorsobronchi and ventrobronchi. These posterior air sacs act as bellows ventilating the lung, much more than the anterior air sacs which are connected to single ventrobronchi. The posterior thoracic air sac is connected to one large laterobronchus. The primary bronchus enters the lung, giving off at the hilus 4 ventrobronchi and, posteriorly, 7 to 10 dorsobronchi besides some laterobronchi, before it enters the abdominal air sac. The avian lung is firmly attached to the thoracic wall and remains constant in volume during both phases of respiration. Besides measurements of the fractional distribution of the volumes of the lung and the air sacs, the exchange surface of the air capillaries was determined in 8 species. Injection casts of the lung air sac system of 155 species of 47 families of birds were studied, together with preparations of fixed specimens of 45 species.