The function of human hair?

Hair is an important part of the human body. It is accompanied by beautiful hair since the baby was born. Hair is an appendage of the skin. Hair plays a very important role in people's life.

Beauty function: having a bright black hair, neatly trimmed and transparent, gives people a chic, elegant and beautiful enjoyment when presented to everyone; On the contrary, if it is fluffy and dirty, it will give people an unpleasant sense of party.

protection: thousands of hairs wrap around the head, naturally forming the first line of defense of the head. Thick, healthy and clean hair can protect the head from external mechanical and bacterial damage, which plays an important role in fitness.

Sensory function: Hair is sensitive. When the external environment has an impact on human body, regardless of wind, rain, sun and fire, the first thing you feel is hair, and the information sent by it is transmitted to your brain, so you can take various protective measures.

regulating function: hair can regulate body temperature. In winter, the cold wind blows, blood vessels contract, and hair can keep the head warm; In summer, the sun is scorching, blood vessels dilate, and hair can radiate heat. Therefore, hair has dual functions of heat preservation and heat dissipation. Hair is a kind of fibrous tissue that grows from the scalp, and it is an arrangement of hard horniness formed by cell regeneration. Hair consists of two parts: root and stem.

The growth rate of hair is 1-2 cm per month, 1-2 cm per year, and the growth cycle is 3-6 years, then it will fall off, and then new hair will grow out in about half a year. Ask for a composition on the topic of "hair"! (5 words)

My father is very ordinary, but to me, he is the most perfect person in the world. He loves my father very much, and my favorite is my father's hair.

Dad's hair is dark and dense, slightly soft, and smells good with the unique fragrance of shampoo.

But I like my father's hair not just for these reasons. When I was a child, I once hurt my leg because I was naughty, which made me cry! My father carried me all the way to the hospital. I grabbed my father's hair and cried because of the pain, but my father just didn't say anything and took me to the hospital with the pain.

I couldn't walk after being put in a plaster in the hospital, so my father would carry me to school every day, lie on my father's back and look at a small scalp exposed by my hair. I felt distressed and guilty, but my father smiled and said that it didn't hurt at all! Smelling the smell of dad's hair feels particularly warm, which will leave a very warm trace in my childhood memory, and I miss it until now.

When I grow up, my father's hair is not as black as before. I'm really worried that my father will become bald. Once, I actually found a lot of white hair in my father's hair, and my heart was very sour, but my father smiled and comforted me that it didn't matter. It was normal when I was old.

I just found out that my father is really much older than when I was a child, and I am growing up! So I smiled and said to my father, when I grow up and earn money, I must buy the best medicine for my father, so that he can grow black and dense hair again! Dad was very happy at that time, and said with a smile, my heart for my father made him happier than growing dark and dense hair! Whenever I think of my father's hair, I can't help but think of those warm memories that my father carried on his back and smelled like his hair. Maybe my father's hair will really fall out one day, but the warm love my father left me will never disappear! The Story of Hair Composition 6 words

Every time I see girls dragging their long ponytails behind their heads and swinging the shiny braided hair, I always feel sad from time to time! My hair used to be very long, too, but because it takes a lot of time to comb it every day, my mother "threatened" me and said, "If you don't cut your hair, I'm afraid my pocket money will be doubled ...!" So I reluctantly walked into the barber shop and watched them slowly cut off my hair. My heart couldn't hurt any more.

After the haircut, at first glance, this hairstyle is the same as that of an old woman in the 196s, and there is no difference.

From then on, endless strange eyes followed me, which made me extremely embarrassed.

On the first day of school after I had my hair cut, I walked into the classroom with a feeling of anxiety. After I opened the door, everyone was amazed, and at the same time, I gave a very strange look, even caused onlookers. I really wish I wouldn't have this head! But it doesn't help. I can't adapt to the "neighbors" when I walk to my seat.

Chen Yingxia sat on the seat with her schoolbag on her back and asked strangely, "Where is Zhang Xiaomei? Who is that in front of me?" Zhong Jiahao said with a smile, "If it isn't Zhang Xiaomei! Who else! " Chen Yingxia suddenly ran over and looked me up and down, so she was surprised and asked, "Oh, my God! No! " I said, "Why not! The world is crazy. It's wrong to have long hair. Even my mother threatened me. Forget it! Don't say it, the more you say it, the more sad it is! " The day after my haircut is the most unforgettable in my life. Fortunately! Now the students are used to it, otherwise! I'll have to dig a hole and get in! I miss my long hair very much, and I can't help thinking: hair! You grow a little longer! Go back to your old long hair! After a few months, I'll grow my hair and I won't cut it if I die! Hair story composition

The sun shines warmly on the earth, the breeze blows, and that hair is blown up and flutters in the wind, shining golden light under the sunlight.

Many years ago that night, a girl (boy) was crying in the silent night, and a beautiful woman was awakened. The woman hurried to the girl's side and stroked her forehead.

The scalding temperature surprised the woman. The woman picked up the girl and ran all the way to the hospital. On the way, the girl lay on the woman's back, smelling the fragrance of shampoo from that long hair.

In confusion, the girl listened to the woman's shortness of breath, and I don't know how long it took ..... Later, the girl went to primary school, and every day when she came home, she could smell the smell of food coming from the kitchen.

Girls always run to the kitchen and give women a big hug. Women always pick up girls and ask them how their day is going.

Every time a girl hugs, she can always smell the smell of food and oil smoke in a woman's hair.

Later, the girl went to junior high school.

The girl has formed a group of friends and always comes home late. The woman asked the girl why she came home so late that day, and the girl yelled at her. You are really annoying.

So the woman and the girl had a big fight.

The girl slammed everything on the desk to the ground.

the next day, it began to rain, and all my friends didn't bring umbrellas.

The girl had to wait for the rain to stop with her friends.

A woman appeared in the rain with a blue umbrella. The girl asked, What are you doing here? The woman put the blue umbrella in the girl's hand, said, Don't get caught in the rain, and rushed into the rain. The black hair was ruthlessly wet by the rain ... The girl cried.

when she got home, the girl saw the woman quietly blowing her hair, and the smell of rain wafted faintly.

the girl said, let me help you.

woman, smile.

The girl picked up the air duct and gently dried the woman's hair. The wet black hair stuck to each other, and dozens of pieces of silver and white were mixed in the dark. The girl cried silently. "You have white hair." "Yes, mom is old.

""I'm sorry ","I'm the one who should say I'm sorry, son, you've grown up ... "Mother, take time as water and love as sunshine, irrigate me and watch me grow.

the black hair is gone, and the years have dyed the black white. Hair Story Composition 6 words

Spread all the hair, which refers to the hair growing on the head.

hair is not an organ, so it contains no nerves and blood vessels, but cells.

hair is mainly used to protect the head, besides enhancing the sense of beauty.

Soft and fluffy hair is elastic, which can resist light collision and help the evaporation of sweat from the head.

The average person has about 1, hairs. Among all hairs, the length of hair is the longest, especially for women with long hair.

some of them can grow to 9-1 cm, or even 15cm, but generally they will not exceed 2cm.

The color of hair is generally determined by genes, such as black, golden yellow, brown and red.

when people get older, their hair usually turns silvery white.

Due to different races and regions, there are black hair, golden hair, reddish brown hair, reddish brown hair, yellowish hair, gray hair, and even green hair and red hair.

you can also dye your hair in various colors by dyeing it.

scientific research has proved that the color of hair is related to the difference of metal elements contained in hair.

Black hair contains equal amounts of copper, iron and melanin. When the content of nickel increases, it will turn gray.

blond hair contains titanium, reddish brown hair contains molybdenum, reddish brown hair contains cobalt besides copper and iron, and green hair contains too much copper.

In some African countries, some children have red hair, which is caused by the serious lack of protein.

from bottom to top, hair can be divided into four parts: hair follicle, hair root and hair shaft.

The physiological characteristics and functions of hair mainly depend on the hair below the scalp epidermis, hair follicles and sebaceous glands.

Hair follicle is the part of hair root in dermis, which is composed of inner hair root sheath, outer hair root sheath and hair bulb. The inner hair root sheath is the sheath layer directly adjacent to hair in the late stage of hair development.

The inner hair root sheath is a stiff, thick-walled keratinized tube, which determines the shape of the cross section when the hair grows.

The lower part of the inner hair sheath has three layers: HUXLEY sheath, HENLE sheath and the surface layer of the inner hair root sheath.

Before hair keratinization, the inner hair root sheath grows with hair, and its source is the cells propagated at the bottom of hair follicle.

near the epidermis, the inner hair root sheath is detached from the epidermis and hair follicle.

Hair * * * is the lowest end of hair follicle, which is connected with capillaries and nerve endings.

At the bottom of hair follicle, epidermal cells divide and differentiate constantly.

These epidermal cells differentiate in different ways, forming different hair components (such as cortex, epidermis and medulla), and the outermost cells form the inner hair root sheath.

at this stage, the cells are soft and non-keratinized.

The function of sebaceous glands is to secrete sebum, which is extruded through the sebum tube. When hair passes through the sebum tube, it takes away the sebum extruded from the sebum tube.

sebum provides natural protection for hair, giving it luster and waterproof performance.

the hairy muscle is a very small muscle organ connected with the epidermis, which depends on the external physiological environment. The hairy muscle can stretch or contract.

The temperature drop or the action of adrenal hormones can pull the hair follicle to a higher position and make the hair stand up.

Hair cortex is the main component of hair, which is composed of slender cells parallel to the long axis of hair.

In these cells, there are about 1 mm tension filaments and interfiber matrix, which determine the main physiological characteristics of hair.

Filaments are composed of fibrin, in which 5% of protein is helical, and the matrix is composed of non-spirochete proteins rich in cystine.

These protein are synthesized at the lower end of hair follicle, and cysteine in the final stage of synthesis is converted into cystine.

the physical properties of hair are related to its chemical composition.

When the hair is soaked in water, it will swell quickly, and the weight after swelling is about 4% higher than that before soaking. This phenomenon of swelling in water shows that the hair is almost pure protein component, and the lipid content is very small.

Hair has strong duality, which is because the arrangement of filaments in cells is parallel to the long axis of hair.

I hope I can help you solve your doubts. The story of composition hair

unfold all 1 "Well, now please close your eyes and tell me how long it's been since you cut your hair.

don't be shy.

"Today I'm going to tell the story of hair.

In the process of human evolution, perhaps the brain is too important to make the hair shrink into hairs, to keep warm, and to add a lot of security.

But not all. There is a profession called "Monks". They don't seem to worship Darwin.

It's not easy to join this profession. Use a knife to shave off the hair on your top, leaving only a bare top. If you are born with a good top, plus superb knife skills, you may even save money on mirrors ―― this is a joke.

Of course, you're not a monk, and I'm not a monk. Let's not talk about monks.

Looking at history, there are many stories about hair.

it was once regarded as a symbol of political power.

Just after the Qing soldiers entered the customs, when the Manchu became emperor, a vigorous "braid revolution" started. The Manchu asked the Han people to wear long braids, but the Han people had to keep them. After all, they were "dependent". Who called them conquered people? Of course, there are a few people who are willing to "fight against the Qing Dynasty and regain sight" but unable to do so, and they use "braiding" to show their resistance, and the end can be imagined.

it's also the Qing dynasty.

As soon as the Opium War started, the restless Han people couldn't sit still and revived.

Jesus' younger brother "stooped down" to be reincarnated in China, gathered a crowd of plows and hoes, and changed his name to rebel in the far southwest.

The first thing they did when they rebelled was to scrap their braids and have long hair, which the Qing army called "long hair".

When the "heavenly soldiers" were destroyed and the Qing emperor was abolished, "foreign water" poured in.

First, some students studying abroad put oil on their hair, which is shiny and eye-catching. Some people who don't like it are called "fake foreign devils".

After the founding of New China and the reform and opening up, "foreign water" can no longer be called "foreign water", but it should be called "foreign trade".

The descendant of Hair Oil, a kind of mousse, came to China. It is also a sticky thing, which is rubbed up assiduously, just like opium in those days. Once some people get it, it seems that they can never let it go, and mousse has become an indispensable part of their lives.

Today, if you look at the people around me, nine out of ten people have divided good hair into ten parts, or left four right six, or left three right seven, or-let it be divided, which seriously violates the natural growth law of hair.

Of course, it is not easy to achieve this effect. After all, nature is great, but it can also be changed by human beings, so mousse will exert its power. A little thing can make hair as hard as a needle.

it's a pity that my hair has to suffer like this! It's spring, let your scalp bathe in the spring, and shave your long hair shorter, maybe you'll be surprised that your image is better.

2 The Story of Hair When she entered the classroom last week, she said, Teacher, can you leave your hat on? She wore a white wool duck tongue.