Owls almost lightning speed to turn his head 180 degrees, because of specialized vessels in their neck-protected zones during sudden movements of the head, say biologists in a paper published in the journal Science.
"Until now, neuroscientists, including myself, did not understand why the forest is not littered with the corpses of thousands of owls that were to be the victims of strokes due to their inherent sharp and rapid head movements. Carotid and vertebral arteries in most animals, including human and owls are vulnerable to even small breaks "- said Philip Gellud (Philippe Gailloud) of Johns Hopkins in Baltimore (USA).
Gellud and his colleagues discovered the secret of unusual strength and flexibility of the neck vessels with "birds of wisdom", the structure of blood vessels and the neck vertebrae in 12 dead owls, purchased in the educational centers in Michigan and Missouri. During the experiments, biologists simulated blood flow in the neck of birds with a special radioactive "jelly", which they filled vessels of the neck joint.
CT scans showed that the arteries birds were markedly different in structure from those of blood vessels in the neck of the other animals. First, they contain a highly flexible "pockets" that can expand and store a blood. Second, the carotid and vertebral arteries were connected to each other with respect to a grid of small blood vessels, allowing equalize the pressure inside them.
In addition, special arrangements for the sharp turns of the head, and contained the bones of the spine and skull. Thus, the holes in the vertebrae, through which passed the arteries were 10 times greater vessels, and bird skull contains some additional "inputs" and "outputs" of the arteries and veins.
The authors used the data to create an information poster, which describes all the tools to protect owls from stroke and ruptured blood vessels with sharp angles. This scientific poster was the winner of the annual competition Visualisation Challenge, which is held the journal Science and the U.S. National Science Foundation (NSF).