Why do people grow hair?

Hair is indeed a special substance. It is an appendage of the skin and is composed of cells filled with keratin. Keratin is also found in the harder tissues of fingernails and toenails. Hair usually grows anywhere except on the palms of the hands, soles of the feet, lips, and vagina.

Each hair is fixed in a tiny hair follicle under the skin. The shape of the hair follicle affects the shape of the hair. Round hair follicles produce straight hair, oval hair follicles produce wavy hair, and those with curly hair have spiral hair follicles. The hair itself is divided into 3 layers.

The pigments that determine hair color are found in the middle layer called the cortex. Black, brown, and blond hair contain varying concentrations of melanin, but red hair contains another type of iron-containing hair iron pigment that resembles blood and rust.

As time goes by, cortical cells will stop producing pigment, and the hair will turn white. Gray hair doesn't actually exist - it's actually a mixture of gray hair and hair of your original color. Hair bleaching usually uses a dilute hydrogen peroxide solution, which destroys these pigment molecules and converts them into a colorless state.

The outermost layer of hair, the cuticle, is composed of overlapping layers of scale cells that reflect light, giving hair its natural luster. The sebaceous glands connected to the hair follicles secrete oil, which lubricates and protects the cuticle; the amount of oil secreted determines whether the hair is dry or oily.

It may seem strange that the human body would go to such trouble to create such a complex substance as hair, since no one knows exactly what hair actually does. Human hair is much longer than that of any other primate. Hair may have been an important species identifier, but it no longer has any real existential value for humans.

Hair has social and cultural significance and is an important part of our personal appearance

What is the function of hair?

Human hair has many functions: it can withstand direct exposure to ultraviolet rays from the sun or cold invasion, repel cold and keep warm, protect from the sun, reduce impact, and protect the scalp and brain.

In today's society, hair has become an important part of people's appearance. By trimming and combing hair, women's hair can be made black and shiny, with graceful and changeable hairstyles, just like wearing a crown, making them more delicate and beautiful; men's hair can be made black and thick, making them appear strong, energetic, smart and capable of masculine beauty.

Why do people have hair on their heads?

Hair is an important part of the human body. It has been accompanied by beautiful hair since birth. Hair is an appendage of the skin. Hair plays a very important role in people's lives.

Beauty effect: Have a head of bright black hair, neatly trimmed and transparent in length and length. When presented in front of everyone, it gives people a free, elegant and beautiful enjoyment; on the contrary, if it is made fluffy and sloppy, , dirty and dirty will give people an unpleasant feeling.

Protection: Thousands of hairs wrap around the skull, naturally forming the first line of defense for the head. Thick, healthy, and clean hair protects the head from external mechanical and bacterial damage and plays an important role in fitness.

Sensory effect: Hair is relatively sensitive. When the external environment affects the human body, whether it is wind, rain, sun or fire, the first thing you feel is the hair, and the information it sends out transmitted to the brain, thereby taking a variety of protective measures.

Regulatory effect: Hair can regulate body temperature. In winter, when the cold wind and the blood vessels constrict, the hair can keep the head a certain amount of heat; in summer, when the sun is scorching, the blood vessels expand, and the hair can dissipate heat. Therefore, hair has the dual function of retaining heat and dissipating heat. Hair is a fibrous tissue that grows from the scalp and is an arrangement of hard cuticles formed by cell regeneration. Hair is composed of two parts: hair root and hair shaft.

Why don’t people with long hair grow taller?

Height is only related to growth hormone, nutrients required for bones, and the environment for bone growth, and has nothing to do with hair.

Generally speaking, girls basically stop growing at the age of 18. You need to exercise more (basketball, rope skipping, etc.) *** For bone growth, eat more bone-based foods (cartilage, tendons) to supplement nutrients to continue to grow taller.

Why do people have long hair?

In the process of human evolution, that is, when humans are standing, their heads face directly towards the sun and are directly affected by the negative effects of precipitation on their heads. Especially after humans stand up, the head becomes the highest point of the human body, making the head the softest underbelly of the body. In order to make up for the disadvantages caused by the weakness to human evolution, evolution has caused the hair in other places to be damaged during the evolution process. It is gradually eliminated, and the hair on the head is not only not eliminated in the process of evolution, but continues to grow into hair. The hair over the shoulders not only protects the head in all directions and plays an early warning role, For example, it can keep your ears warm in winter, etc. The hair that goes over your shoulders can also serve as an early warning or protection for your neck. Of course, with the development of human beings, the weakness of the head has long been compensated by civilization, that is, the function of hair has long been replaced by civilization, turning the original function of hair into the beautiful function of today's human beings. This means that people grow hair in order to adapt to the natural environment and to adapt to the changing needs of human beings in the process of evolution, so people grow hair.

Why do people have long hair? What are the benefits of hair to people

Hair can only grow on the head. Under a microscope, the hair follicles of the hair plucked from the thighs look the same as the hair follicles. Anatomically, our The hair on your armpits, legs, and other parts of your body is the same thing as hair. However, hair transplant experiments show that the location of the hair determines how it grows. When people perform hair transplantation, they often take a piece of hair from one place on the head and transplant it to another place on the head, because if the hair is transplanted from other parts of the body, it will not be successful. Similarly, if the hair is transplanted to the body In other parts of the body, hair will not grow smoothly either. Dr. Neufeld said: "When researchers transplant hair from the head to the legs, the hair will not grow as long as on the head, but the hair transplanted to the legs will be longer than typical leg hair. Grow longer. " Hair and body hair grow in cycles. During the active phase called "anagen", the hair follicle will grow a strand of hair, and then the growth rate will slow down and the hair follicle will "rest" "For a while, this stage was called the "telogen" stage. When hair falls out, it reaches the "exogen" stage. When "anagen" starts again, the hair follicle will grow a new strand of hair. Hair on legs typically grows for 19 to 26 weeks and then falls out, while hair can continue to grow for 2 to 6 years.

Hope to adopt

Why does my hair grow quickly

Hair is the fastest growing hair, generally growing 0.27-0.4mm per day, with an average of 0.27-0.4mm per month. The growth is about 1.0cm, and it grows about 10-14cm in a year.

The hair growth rate is mainly affected by the following:

(1) Glands

① Gonads: Male hormones play an important role in the growth of hair mother cells .

②Adrenal gland: If the secretion of male hormones from the adrenal cortex is strong, it can cause hirsutism in women. But it is also related to the function of the pituitary gland. If the function of the pituitary gland deteriorates, hair may decrease or fall out.

③Thyroid: Whether the thyroid function is normal or not, plays an important role in hair growth. If its function is dysfunctional, the hair in the outer 1/3 of the eyebrows and the temporal part will fall off. When the function decreases, not only the color will fade and become gray-white, but the hair will also decrease or fall off. The growth and shedding of hair are mainly controlled by the growth phase of the hair itself, but are also affected by other factors such as race, endocrine, disease, mental status, gender, age, season and other factors.

(1) Race: Racial differences are a relatively obvious phenomenon. People of different races not only have different hair colors, but also different hair lengths and growth conditions. Baldness is very common among Caucasians, less common among Chinese, and even rarer among Indians. (2) Heredity: In the same family, hair growth conditions are often roughly the same. Male pattern baldness is closely related to genetics.

(3) Endocrine: Male hormones can directly act on hair follicles, causing male pattern baldness. This phenomenon will not occur in people who lack male hormones (such as eunuchs).

Estrogen antagonizes androgens, so women rarely experience baldness before menopause. When thyroid hormone is insufficient, hair becomes sparse, when adrenal gland function is low, hair loss occurs, and anterior pituitary gland hypofunction can lead to total hair loss.

(4) Mental status: Nervousness, fear, anxiety, etc. can significantly increase hair loss. According to reports, one death row prisoner lost more than 1,000 hair strands every day after he was sentenced.

(5) Vitamins: Long-term lack of vitamin A can lead to thinning of hair; lack of vitamin B2 can lead to increased seborrhea, and hair can easily fall off; lack of vitamin B6 can cause abnormal sebum secretion, oral administration Birth control pills can speed up metabolism and consume more vitamin B6, which may be related to diffuse hair loss in some women. In addition, vitamin B6 can affect the pigment metabolism process. When lacking, the hair will turn gray and have poor growth; when pantothenic acid (also known as vitamin B3) is lacking, the hair will turn white and have poor growth; inositol belongs to the vitamin B family and can prevent hair loss. ; Biotin (also known as vitamin H2) deficiency can cause hair loss; para-aminobenzoic acid is also a B vitamin, which can protect hair color and maintain normal hair growth. (6) Trace elements: Some scholars have observed changes in the values ??of trace elements zinc, iron, molybdenum, calcium, lead, magnesium, manganese and selenium in hair and found that the values ??of zinc, copper, iron and manganese in patients with hair loss were significantly reduced, while the values ??of calcium, magnesium and , Selenium value was significantly increased, and there was no difference in the value of each element in patients with atypical hair loss. Copper deficiency will affect the absorption and utilization of iron. Poor iron metabolism will cause symptoms such as anemia and mental agitation. The latter can be a contributing factor to alopecia areata. Copper deficiency will also affect the keratinization process of hair, thereby affecting hair growth; calcium passes through It binds to calponin and plays a role. High calcium concentration may change the immune regulatory function of the central nervous system, thereby causing hair loss; excessive selenium can cause hair loss due to autoimmune reactions and increased scalp seborrheic.

(7) Disease: Certain systemic diseases, such as febrile diseases, anemia, malnutrition, liver disease and severe chronic wasting diseases, can often lead to thinning hair.

(8) Gender and age: Women’s hair grows faster than men, and young people grow faster than old people, but this difference is not very big. As age increases, the number of hair follicles on the head decreases more. Significantly. According to statistics, based on the number of hair follicles per square centimeter, there are 615 hair follicles in 20-30 years old, 485 hair follicles in 30-50 years old, and 435 hair follicles in 80-90 years old.

(9) Other factors: Hair grows slightly faster in summer than in winter. This is because the rise in temperature can promote strong metabolism, leading to accelerated hair growth. Hair grows slightly faster during the day than at night. X-rays can control sulfhydryl compounds in the hair follicle matrix, causing temporary hair loss. Certain chemical factors such as iron can affect keratinization and may interfere with cystine's participation in the composition of keratin, thereby affecting hair growth. Ultraviolet rays, drugs, trauma, chronic inflammation, skin diseases, topical acne, etc., also have a certain impact on hair growth and shedding. ...

Why do people have long hair?

Even if I don’t say that you are a talented person~~

The master of the barber shop has to make a living! Hehe, just kidding

Hair is indeed a special substance. It is an appendage of the skin and is composed of cells filled with keratin. Keratin is also found in the harder tissues of fingernails and toenails. Hair usually grows anywhere except on the palms of the hands, soles of the feet, lips, and vagina.

Each hair is fixed in a tiny hair follicle under the skin. The shape of the hair follicle affects the shape of the hair. Round hair follicles produce straight hair, oval hair follicles produce wavy hair, and those with curly hair have spiral hair follicles. The hair itself is divided into 3 layers.

The pigments that determine hair color are found in the middle layer called the cortex. Black, brown, and blond hair contain varying concentrations of melanin, but red hair contains another type of iron-containing hair iron pigment that resembles blood and rust.

As time goes by, cortical cells will stop producing pigment, and the hair will turn white. Gray hair doesn't actually exist - it's actually a mixture of gray hair and hair of your original color. Hair bleaching usually uses a dilute hydrogen peroxide solution, which destroys these pigment molecules and converts them into a colorless state.

The outermost layer of hair, the cuticle, is composed of overlapping layers of scale cells that reflect light, giving hair its natural luster.

The sebaceous glands connected to the hair follicles secrete oil, which lubricates and protects the cuticle; the amount of oil secreted determines whether the hair is dry or oily.

It may seem strange that the human body would go to such trouble to create such a complex substance as hair, since no one knows exactly what hair actually does. Human hair is much longer than that of any other primate. Hair may have been an important species identifier, but it no longer has any real existential value for humans.

Hair has social and cultural significance and is an important part of our personal appearance

What is the function of hair?

Human hair has many functions: it can withstand direct exposure to ultraviolet rays from the sun or cold invasion, repel cold and keep warm, protect from the sun, reduce impact, and protect the scalp and brain.

In today's society, hair has become an important part of people's appearance. By trimming and combing hair, women's hair can be made black and shiny, with graceful and changeable hairstyles, just like wearing a crown, making them more delicate and beautiful; men's hair can be made black and thick, making them appear strong, energetic, smart and capable of masculine beauty.

Why do people keep growing their hair?

I have always wondered why people keep growing their hair. If it is a question of animal evolution, in the process of evolution from monkeys to humans, the hair on the body has gradually degenerated or almost disappeared, but the hair growth has been continuously strengthened. It belongs to the category of "wild fire cannot burn it out, but the spring breeze blows it again." type. Looking at all the animals in the world, there is no continuous hair growth. Do humans have the genes of lions? But even a male lion's hair stops growing after it reaches a certain length. From the perspective of the laws of survival in nature, some people say that many ancient people wore animal skins and few wore animal hats, so the body hair degenerated due to the loss of protective function, while the hair was retained or strengthened due to the need to keep warm, but this does not make sense. . According to experts, the head is the tissue that is least afraid of severe cold. Maybe everyone feels this way. I once had the experience of washing my hair with cold water on a snowy day, and I didn't feel that I was too cold. However, taking a cold shower is out of the question, unless my brain is broken. I suddenly felt that all this might be God's arrangement, so that some people can have a living to support their families. It is precisely because people have hair, and it keeps growing, that's why there are barbers or people who are now called A profession known as hairdresser emerged. When you are busy all day long, you have a reason to get a haircut to avoid work. When you have too much money to spend, someone will spend it or transfer it for you, and also cut the leeks on your head. Drop a crop. And you also stupidly said "the cut is beautiful". At this point, I actually had a very vicious thought. Anyway, today's advanced technology allows those who want to win the "Nobel Prize" to invent a drug that can stop hair from growing, or even prevent any hair from growing. In that case, the whole world will be dazzling during the day, and how much energy can be saved at night, haha! (Except Africa, which can only be blamed on their ancestors). If this were the case, the inventor would probably even win the "Nobel Prize for Environmental Protection." Having said this, I may be bored, because in today's gossip, if you don't pay attention, your post will be deleted. If you have been busy for a long time, you might as well just move a pig's finger and your own hard work for half a day will be in vain, so you might as well post a boring post. The idea about hair is based on the experience of getting a haircut at an exorbitant price of 12,000 yuan that happened in Zhengzhou two days ago.

Why does human hair grow long?

The hair that makes scientists scratch their heads. When you go to the library to look for answers one day, you will find that except for musk oxen, humans are almost the only An animal whose hair grows all the time. Why is this? But you won't find the answer on the library shelves, because no one has been able to solve the mystery so far. Over the past few years, scientists have become increasingly interested in studying human hair. A short article published in the American journal "Evolutionary Anthropology" is the first to explore this issue. It was written by physiologist Arthur Neufeld of Northwestern University and anthropologist Glenn Kang of Washington University in St. Louis. Co-written by Roy ***. They pointed out that the hair of other mammals stops growing automatically when it reaches a certain length, but human hair continues to grow. They asked in the article: "Have you ever seen a chimpanzee grooming its hair? Or have you ever seen any long-haired animal needing to have its hair cut?" Of course not.

Why can human hair continue to grow? Not much is currently known about this issue. Hair grows on all surfaces of the human body except the palms and soles of the feet. Human hair can be divided into soft hair and hard hair according to thickness, softness and hardness. Soft hair, commonly known as fine hair, is soft and light in color and spreads over the surface of the skin; hard hair is thick and hard and grows in certain parts of the human body, such as hair. In adults, under the control of complex hormonal mechanisms, these two types of hair can expand into a variety of hairs, such as eyebrows, eyelashes, armpit hair, and beards. Whether it is smooth hair or tiny toe hair, it can grow at a rate of 1 to 1.5 centimeters per month. The hair stops growing for a very short time before falling off. Hairs have different lifespans in different parts of the body, which determines their ultimate length. For example, leg hair can continue to grow for about 2 months and armpit hair for up to 6 months, but hair can continue to grow for 6 years or more. When hair grows to a certain stage, it begins to fall out and be replaced. The replacement of human hair is not seasonal like that of mammals, but it is gradually shed and replaced frequently throughout life. According to statistics, there are 100,000 to 200,000 human hairs, including 80,000 to 140,000 on the head, 20,000 on the trunk and limbs, and 30 to 120 hairs are shed every day. The lifespan of hair in different parts of the body varies: hair has a lifespan of 2 to 5 years; beards have a lifespan of 2 to 3 years; armpit hair has a lifespan of 1 to 2 years; *** 1 to 1.5 years (some say beard, armpit hair, ** *The lifespan is only 7 to 10 months); the lifespan of eyebrows and eyelashes is 3 to 5 months. In addition to natural shedding at the end of life, hair can also fall off due to poisoning, disease or violence. Gene mutation may be the main reason. As for how to control hair growth, there are still many uncertain factors, and scientists have not yet solved some mysteries. But hair growth may be related to countless genes. And, changes in even one gene can have a huge impact on hair growth. Taking the Angora rat as an example, its long hair is related to a genetic mutation called FGF5, which is a protein that stops hair growth. Neufeld and Conroy believe that the reason why human hair continues to grow may be due to mutations in FGF5 or similar genes, which lose their ability to inhibit hair growth. Another possibility is that the genes for the 10 major keratins (an insoluble, harder protein substance that is the main structural component of hair, nails, horns and hooves) contained in hair are continuously copied. Scientists pointed out that nine of the keratins are almost identical in humans, chimpanzees and gorillas, but the tenth one - phi-hHaA - is significantly different. Although for humans, phi-hHaA is a pseudogenetic factor (that is, it is a part of the deoxyribonucleic acid DNA, similar to a genetic factor but has no genetic function and cannot synthesize proteins), in other primates it is a mutable of protein. Helmilita Wendt of the German Cancer Research Center published his findings in 2001: This gene mutation appeared 240,000 years ago. Which is more attractive, short hair or long hair? Short hair has many benefits compared with long hair: first, it is more beneficial to health, because long hair is more likely to breed parasites; in addition, it is very helpful in regulating body temperature. Short hair would have allowed our ancestors to better adapt to climates ranging from jungles to savannahs. Some people even believe that keeping short hair is a way for ancestors to adapt to life by the water. Darwin believed that sexual orientation was the key: People with short hair looked more attractive than those with long hair, so they had more offspring, and their population increased, while fewer and fewer people had long hair.

Although short hair has many benefits, the fact is that humans prefer long hair, and hair has become thicker during evolution. You need to know...

Why do women keep long hair

At that time, it was because the hair and skin of the body were given to parents..

Later in the Qing Dynasty, more and more Chinese people studied abroad.

Many young people are aware of the progress of foreign countries and want to learn from their advancement.

Just like the change in clothing, men began to wear suits...

From life, In food, thought and other aspects, China learned from foreign countries. Men cut off their braids.

But women still kept them. Women had not yet been truly liberated at that time, and cutting hair was still considered unethical.< /p>

It may be due to women’s personality that they all have long hair now..

On the one hand, it clearly identifies gender.

On the other hand, women’s hair also The most natural decoration.

Furthermore, it is also an aesthetic habit.

The long and graceful women in Chinese costume dramas indeed contain oriental beauty.

Western blond hair and blue eyes are also sexy and charming..