The human body is a complex and secret "machine" with many secrets. Although human beings are constantly exploring, they have only discovered a few secrets, and many have not yet been discovered, and these "small parts" are for us to know ourselves. The body plays a huge role.
1. Your heartbeat is only 3 billion times in a lifetime
For a normal person, the number of heartbeats in a lifetime is about 3 billion. Therefore, protecting the heart is very important for everyone. Now that cardiovascular and heart diseases are beginning to be younger, everyone should be prevented.
2. The speed at which the sneeze spreads is 100 mph
If you encounter someone sneezing in the subway, you should wear a mask even if you are not with you. Because the spread of bacteria in human sneezes is 100 miles per hour. If you are in a car, a sneeze will spread bacteria throughout the car, so remember to wear a mask in a crowded area.
3. 1/3 of the water is hidden in human bones
In addition to muscles, bones, blood, etc., the human body is mainly composed of water. The proportion of body fluids in the body of adult women is about 55%, and that of men is 60%. But human body fluids are not only stored in the skin, muscles, blood vessels, and organs, but also in the bones. In fact, the water in the bones accounts for 1/3 of the total body water.
4. There are as many bacteria as cells in humans
A normal person has about 38 trillion cells, and you may not know that the total number of bacteria on the body is about the same as the number of human cells. If all the bacteria are aggregated together, it is about 225 grams.
5. How many human hairs are there?
Many people have a silly question when they are young: How many hairs are there? Now I finally know. The American Academy of Dermatology points out: People are born with 5 million hair follicles, of which more than 100,000 are located on the scalp. According to a rough estimate, a person has more than 100,000 hairs. And the hair renewal speed of men is faster than that of women, except of course for baldness.
6. How many times does a person breathe a day?
Exhaling and inhaling are basic physiological activities of human beings, but do you know how many times you breathe every day? People breathe between 17,280 and 23,040 times a day. This reminds us that people’s breathing frequency is different. Improving lung health can make one’s breathing healthier.
7. The surface area of the lungs is too big for you to imagine
Human lungs are basically the same size, but special populations have larger lungs and stronger functions, such as athletes. What you don't know is that the surface area of our lungs is so large that we can't imagine that the surface area of all the lung lobes can cover a badminton court or half a tennis court.
8. Why do you cut your fingernails more frequently than your toenails?
We often cut our fingernails, but it takes a long time to cut our toenails. Why? It turns out that the growth rate of toenails is slower than that of snails. Toenails can only grow by 1 mm per month, while fingernails grow by 0.1 mm per day, which is 3 mm per month.
9. Human taste memory has the longest time
The sweet and bitter taste is felt through the human tongue. There are 2000 to 8000 taste buds on the human tongue, and each taste bud has 50 to 100 taste receptor cells. When we eat, we use these taste buds to convey the taste to the brain. This kind of taste memory has the longest time, so even after decades of separation, we will still remember the taste of our childhood.
10. A woman has only 500 mature eggs in her lifetime
When a woman is born, there are 1 million to 2 million eggs in the ovaries, but these eggs will not always exist intact. As they age, they will decrease year by year until menopause. During the entire reproductive period, there are only 500 mature eggs. Therefore, if women want children, it is best not to miss the best fertility period.