The structure of the human body is very complex, and there are many magical and interesting little secrets hidden that are worth exploring and discovering. Today Xiaobian will talk about a few body cold knowledge that you may not know, and take you to explore the mysteries of the human body together.
Why do people always have a handful of snot and a handful of tears when they cry?
We all know that when we cry, tears often flow down with snot, why is this?
In fact, when people cry, what flows from their noses is not snot, but tears, because people have "tear devices". The lacrimal vessel is an auxiliary device of the eye, consisting of lacrimal glands and lacriculus. Among them, the lacrimal glands include lacrimal dots, lacrimal ducts, lacrimal sacs and nasolacrimal ducts. We can look at the side of the upper and lower eyelid edges near the nose, and we will find that there is a small hole in this place on each side, and this small hole is the tear dot.
When people cry, the tears secreted by the tear glands will increase sharply, in addition to the tears flowing from the eye sockets, other tears will pass through the tear points and enter the nasal cavity through the nasal tear tube, which is why people will "snot a handful of tears" when crying.
Why do people only have their fingers and toes wrinkled after soaking in water?
We all know that after people soak in water for a long time, their fingers and toes will wrinkle, why is this? Some people say that it is because the skin absorbs water and swells, but this does not explain why the rest of our body does not wrinkle.
The real cause of wrinkles in the skin of the hands and feet should be attributed to the subcutaneous nerves of the hands and feet. When we stay in the water for too long, the subcutaneous nerves of the fingers of the hands and feet will react, leading the rapid contraction of the subcutaneous blood vessels, so the skin is then pulled closer and produces a wrinkle phenomenon, which is also known as the "water wrinkle reaction". This phenomenon is actually a way for people to increase the friction of their hands and feet in order to be in water or in a relatively smooth environment, and it is a kind of stress manifestation produced in order to adapt to the environment in the process of evolution.
Why do people burp?
Hiccups, also known as hiccups, are generally caused by spasm of the diaphragm muscles, which are governed by a "hiccup reflex arc". Usually this reflex arc is silent, but after it is stimulated, such as people gobbling, coughing, laughing, emotional agitation, drinking carbonated drinks, etc., it may be activated, and people will begin to burp.
So why does hiccup stop after the hiccup person is suddenly startled? This is because a sudden fright can interfere with the nerve signaling of this reflex arc and interrupt its reflex, and the hiccup will naturally stop. However, if your hiccups are repeated or exceed 48 hours, this may indicate that your digestive or respiratory function is abnormal, and it is recommended that you go to the hospital to see it at this time.
Why do people get goosebumps?
If we suddenly feel cold in life, we get goosebumps when we hear irritating sounds, fright, etc., what is going on? What we call goosebumps is actually related to a kind of smooth muscle of the hair follicle, also known as "standing hair muscle".
In ancient times, our ancestors did not have any artifacts to resist the cold, and could only protect the skin through body hair, so when the cold struck, in order to better limit the circulation of air outside the surface of the skin, the hair muscles made the body hair stand up through contraction, forming a relatively insulation "small atmosphere" to keep warm. But with the evolution of humans, the hair muscle is also gradually degenerating, becoming a kind of stress management system. When a person is stimulated by the outside world, the trigger sympathetic nerve will send a signal, the skin will respond accordingly, and the "erect hair muscle" will contract to form goosebumps. In other words, goosebumps are actually a reaction to our human body's self-protection.
Having said all this, Xiaobian can't help but sigh that "the human body is really wonderful." You also know what human body cold knowledge, welcome to leave a message in the comment area, share it with you.