How owls turns out to turn the head to 270 degrees?
It is known that owls are excellent predators. And they are equally seen both day and night. Some representatives of the detachment prefer to hunt in the daytime of the day – for example, the polar owl is doing. Yes, and Filin in the afternoon sees further than at night. But still, in the dark, the owls have more benefits before prey, as they have a very good hearing, which allows you to navigate in the dark. True, the ears of the sinks, like eyes, the owls are still. Therefore, to keep track of the victim or in time to notice the danger, the birds learned quite well to twist heads – they can turn her by 270 °. How do they manage not to break the vertebrae and do not block the bloodstream? Due to a number of anatomical features.
Flexibility provides a large number of cervical vertebrae. Owls have 14 (and in humans, for example, only seven). At the same time, the vertebral artery enters the cervical department through the 12th, and not the 14th vertebra, that is, higher than many birds. This provides additional freedom with strong and sharp head turns. But one thing will be able to turn around, and quite another – avoid the consequences.
This helps the peculiarity of the vertebral arteries that feed the brain of owls. They pass through special holes in vertebrae that have additional space. The diameter of such channels from owls is about 10 times wider than the diameter of the arteries passing through them. From 14 cervical vertebrae, vertebral holes are expanded in 12, which avoids the sintering of blood vessels.
But nature still reinsured. Sleepy arteries of owls are connected with spinal special jumpers. One of these jumpers is free trigeminal artery – helps blood flow into the brain without stopping. This is necessary in case the vessels still turn out to be strongly shifted. There is a backup option. Sleepy arteries located in the area of the Lower Jaw, there is a special extension where the blood supply is located. So, if the vessels still stand for a while, the continuity of blood movement does not break. And the network of small vessels, departing from the main arteries, will allow blood if necessary to find an alternative path.
