Science, why don't the woodpecker have a headache?

The coffin is one of the most important activities of the woodpecker. The number of coffins can reach 12,000 times a day, the frequency reaches 20 times per second, and the deceleration force of each impact reaches 1200 times the gravity, which is equivalent to 25 kilometers per hour speed hit the wall. If we humans do as a woodpecker, there is no doubt that it will lead to a series of fatal consequences such as concussion, brain damage, retinal hemorrhage and retinal detachment. How is the woodpecker avoided?

The woodpecker's brain is relatively small, and the surface area of a small object is relatively large. The pressure exerted on it is easy to disperse, so it is not as easy to concussion as the human brain. When the woodpecker is in the coffin, the direction of the tap is very vertical, which can avoid the tearing of the meninges and concussion caused by the torsion caused by the shaking.

Woodpeckers have also evolved a series of devices that protect the brain and the eye from impact. Its skull is very thick, but there are many small gaps in the bones, a bit like a sponge that can reduce vibration. There is a membrane on the surface of the brain called the pia mater. The head of the woodpecker has evolved a series of special structures to prevent vibration damage. There is also a membrane called arachnoid on the outside of it, and a cavity between the two membranes is called the subarachnoid space. The human subarachnoid space is filled with cerebrospinal fluid. However, the subarachnoid space of the woodpecker is very narrow and has almost no cerebrospinal fluid, thus weakening the liquid transmission of the shock wave.

The most amazing thing is the tongue of the woodpecker. Its tongue is extremely long, born from the back of the upper jaw, passes through the right nostril, splits into two, and then wraps around the upper and lower parts of the skull, through the sides of the neck, under the chin, and synthesizes a tongue in the mouth. This tongue is like a rubber band that can shoot 10 cm from the outside. Obviously, the main purpose of this long tongue is to hook the worm out of the hole, but it can absorb the impact force before the chops contract each time, and it is also a good cushioning device.

The body structure of the woodpecker is the result of long-term evolution under the influence of natural selection. It is instructive to study how it can subtly avoid the physical damage caused by impact, and it is very instructive to improve the protection equipment against human brain damage.