I often see the news that 3~4-year-old children accidentally strangled their fingers while playing with rubber bands, and as a result, they forgot to take them off after falling asleep and almost amputated their limbs. If you are an observant, you must have also noticed that when you tighten your fingers with a cowhide band, your fingers will turn cold and purple after a few seconds, and after you remove the cowhide band, your fingers will heat up and turn red.
The little cowhide band is so powerful, what the hell is going on? I'm going to talk to you today.
01, why does the cowhide band turn cold and purple after strangling the fingers?
Why do cowhide bands turn cold and purple after strangling fingers? To put it simply, it's because of the oxygen supply. Why is oxygen supply so critical?
Let's briefly review how the human body is powered by energy. We know that all the energy of the human body comes from cellular respiration, which produces a "universal currency" - ATP
There are two types of ATP:
（1）C6H12O6（葡萄糖） + 6O2 → 6CO2 + 6 H2O + 38 ATP
（2）C6H12O6 （葡萄糖）→ 2C3H6O3 （乳酸） + 2 ATP
Take a closer look at the difference between 1 and 2.
First, the reaction formula on the left has the difference between oxygen and non-oxygen.
1. The first one has oxygen, the second one has no oxygen,
2. The first is aerobic respiration, and the second is anaerobic respiration
Very familiar, many sports bodybuilding experts say all day long to say how long to start anaerobic breathing, in fact, it is. Unless you are under pure oxygen conditions, your body is completely impossible, otherwise, the human body has always coexisted with both. At most, when you exercise at high frequency and high load, when you don't get enough oxygen, your anaerobic breathing will increase, and that's it.
Therefore, if you want to enhance anaerobic breathing, you can increase the frequency of exercise, such as skipping rope and the like.
Second, the product on the right is different.
1. The first one produced 38 ATPs; The second one produced only 2 ATP, so the anaerobic respiration energy was extremely low.
2. The second one produces lactic acid, so if you breathe without oxygen, you will feel sore.
Well, at this point, the principle is actually very clear.
02, why is it cold when tightened, but hot when relaxed?
Because after tightening, the blood circulation cannot be supplied, and the most important role of blood is to carry oxygen.
When there is a lack of oxygen, cellular respiration becomes anaerobic respiration, and the energy is only one-nineteenth of the previous one, so it will inevitably become colder. Once relaxed, the oxygen comes up, and the heating is immediately increased.
Sing with me:
You are snowing in the sun in the south, and I am like spring in the cold night of the north
03, why does it turn purple when tightened, but red when relaxed?
For this question, you can think about the color of the blood. Because of the different oxygen content, arterial blood is rich in oxygen and bright red in color, while venous blood is less oxygenated and dark red in color.
So, when you tighten up, the blood in the local capillaries doesn't come into contact with fresh oxygen, so it gets deeper and deeper. When you let go, the oxygen comes to your face, so you quickly contact the oxygen, so the color returns.
Imagine a medical legend where blue represents veins and red represents arteries.
Finally, a word of advice, don't try, because you can't control the time well, too long will lead to ischemia and necrosis.
Once this happens, it can only be cut.