Unexpected small secrets of the human body – Sohu Education plustek

Unexpected small secrets of the human body – Sohu education this article from the global science magazine, the WeChat public number American global science Scientific (ID: huanqiukexue) authorized reprint. Why is the big noise uncomfortable? Why are bacteria resistant to antibiotics, and humans are not resistant to disease? The "New Scientist" magazine as a collection of all the small problems on the body. The translation of Ding Jiaqi Niu Tianyu. The sound of breaking glass made people feel uneasy, but why? (source: Alamy) for twenty years, a "New Scientist" (New Scientist) magazine will be published for the best answer to some readers problems and other readers are in the back. Here are some questions and answers about people’s bodies. Why don’t we sneeze while we sleep? Sneezing is a conditioned reflex caused by internal or external stimuli. In REM sleep (REM) stage, the brain can not control muscle, and part of the body in a state of paralysis, the reflex disappears, this is to prevent people to hurt others move in a dream. Since the reflex signal doesn’t work, it doesn’t sneeze. If you really have to sneeze, then the relaxation period of REM sleep will end, causing you to wake up before you sneeze. However, some people with REM sleep disorder in REM sleep device can control their movements, even because of hurt or kill others in his sleep and the court case, therefore, estimated that the person is asleep or can sneeze. Why is the noise of the big volume painful? They do not seem to cause physical damage, but it does make people feel very uncomfortable. I had heard the sound of a truck carrying a container of empty bottles, which was so uncomfortable that I had to cover my ears. There are two main reasons why the noise caused by the noise of the glass bottle on the truck is: volume and irregular frequency. The detection of sound in the ear originates from the ciliated cells in the cochlea, which allow the cells to undergo mechanical deformation and deliver an electrical signal from the auditory nerve to the brain. Among them, different ciliated cells are responsible for the response to different frequencies of sound, the bass in the cochlea at the end of the spiral is received and the treble on the other side. If the volume is too high, will cause the chemical depletion process in cell signaling, or mechanical damage, damage the delicate parts. Evolution allows us to think of harmful stimuli as unpleasant and painful feelings, so that we can avoid them effectively. At the same time, the frequency is too similar to the voice can also make people feel very unhappy – imagine the piano on the two adjacent keys together to bring people to bring the sense of discord. This may be due to the fact that the frequency of the cilia in the cochlea is partly covered by the excessive stimulation of the cell. The empty bottle bumps in the car will produce too many discordant sound at the same time, the glass is broken!相关的主题文章: