On the question "Why Birds Fly?" the answer usually follows: "Because they have wings". Meanwhile, cases when in the aspiration to fly up the person invented the wings reminding bird's are known and, having fitted them to a back, tried to fly up, but flight it was impossible. Why? The thing is that birds, besides wings, have a lot more devices for flight.
Instruction
1. Features the skeletavneshny surface of a breast at birds has a keel – a big outgrowth. It is peculiar "fixture" of the pectoral muscles moving wings. At birds the skeleton fortress necessary at flight is provided with accretion of some bones. So, their backbone represents not a mobile flexible chain of separate vertebras (as, for example, at mammals), and a rigid structure in which lumbar vertebras grew together not only among themselves, but also with tail and with sacral vertebras. For creation of a strong support at birds even podvzdoshny bones form fusion with a vertebra. And, at last, at all birds very easy skeleton. The reason of small weight is in pneumatic cavities which a number of bones contains. They are not filled with red marrow as, for example, at people.
2. MuskulaturaGrudnyy muscles make a quarter of body weight of a bird. They raise wings. Bird's muscles are capable to reserve a lot of oxygen, there is it thanks to the high content of protein of a myoglobin (the ferriferous protein which is responsible for transportation of oxygen in skeletal muscles and muscles of heart).
3. Double the dykhaniyedykhatelny device of birds is arranged absolutely differently, than at mammals, including at the person. The inhaled air passes at them through tubes bronchioles in lungs and is delivered in air sacks. On an exhalation air moves from sacks on tubes again through lungs in which gas exchange is again made. Thanks to such double breath, supply of a bird's organism with oxygen increases that is extremely important in flight conditions.
4. Features of the cardiovascular Heart system at all birds are much larger, than at those mammals who have the body size, similar to them. The more the bird flies (for example, flying), the more she has a heart. Large bird's heart reliably provides faster blood-groove (blood circulation). Pulse at birds reaches 1000 beats per minute, and pressure – 180 mm of a mercury column. In blood of a bird there are more erythrocytes, than at many mammals: it means that more oxygen, necessary for flight is transferred to one unit of time. Thanks to perfectly developed systems of a blood-groove and breath, in an organism of birds very quickly there passes the metabolism, for this reason for each bird the high temperature of a body – 40-42 °C is characteristic. At such temperature all processes of activity take place much quicker, including muscular contractions that when flying plays a large role.
5. PeryaMalo who knows that feathers of a bird were once scales of ancient reptiles who then, in the course of evolution, were transformed to horn formation of skin, easy and very difficult on the structure. Exactly thanks to feathers the surface of all body of a bird such smooth and streamline. Feathers help to create the carrying power and draft. During flight, air almost without resistance flows round her smooth trunk. By means of steering feathers of a tail the bird manages to regulate the direction of flight. Besides, feathers keep heat, elastically spring, create the uniform layer protecting birds from negative impacts of the environment — cold, overheating, wind, dampness. This layer also interferes with loss of heat.
6. Actually a krylyaustroystvo of wings of a bird such is that they create force which counteracts force of terrestrial gravitation. The design covered not flat, and curved. Thanks to it, the air stream which is bending around a wing passes on the bottom (concave) side shorter way, than on top (curved). That the air flows bypassing a wing met at its extremity in at one time, air flow over a wing has to move quicker, than under a wing. For this reason the speed of passing of air over a wing increases, and pressure, respectively, decreases. This difference of pressure over and under a wing also forms that carrying power which (directed up) and counteracts gravity.