字幕列表 影片播放 列印英文字幕 Kids Health presents, How The Body Works, with Chloe and the Nurb. Chloe, you'll never guess what I got for all of the money in our piggy bank. Magic beans for growing hair. Why do you want to grow hair? Ah, no reason. Nurb, hair doesn't grow from beans. Chloe, I'm pretty sure it does. Come with me. I'll show you how hair grows. Why are we in the middle of a forest? Does hair come from trees? These aren't trees, Nurb. That's a strand of hair. We're in hair. Hair! What is hair doing here? That's the thing, Nurb. Hair grows almost anywhere. When you think of hair, you probably think of the hair that grows on the head, but there's hair on almost every part of the body. Weird! You mean weirdly awesome! Some of the hair on the body is easy to see, like eyebrows. But other hair, like the hair on the cheek is so fine that it's almost invisible. I have hair on my cheek? Why would my body need that? Depending on where hair is, it has different jobs. The hair on top of my head keeps my head warm. My eyelashes protect my eyes from dirt and dust. And your eyebrows-- --attract the lady nurbs. And protect your eyes from sweat dripping down into them. Amazing. But if this hair stuff is everywhere, where does it come from? It all starts in the skin. So that's where the magic beans are planted. No beans, Nurb. Ah, you stupid good for nothing beans, I curse the day I bought you. Please continue. There are tube like hair follicles that extend below the surface of the skin. At the base of each follicle is the hair bulb, where cells multiply. As hair begins to grow, it pushes up and out of the follicle, through the skin, where it can be seen. That's amazing. Even more amazing is that once hair is at the skin surface, the cells that make up a strand of hair aren't alive anymore. That's why it doesn't hurt when hair is cut with scissors. Dead cells? Why does it look so pretty and shiny? For that you can thank the oil glands, which are also called sebaceous glands. Fancy word. The sebaceous glands produce the oil that makes hair shiny. Sometimes the sebaceous gland pumps out too much oil and the person's hair may look greasy. Greasy? Oh let me touch! Let me touch! Oh no! What have I done to the beautiful hair? You didn't do anything Nurb. You may not notice it, but hair is always falling out and being replaced by new hair. Each hair grows for an average of about three years, lives for a few months, and then it falls out. A new hair grows out of the same follicle, replacing the old one. Of the 100,000 hairs on a typical person's head, about 50 to 100 hairs fall out each day. That's neat. Why is this one black though? Hair comes in all sorts of different colors. Hair color comes from melanin which is a pigment. The lighter someone's hair is, the less melanin there is. So someone with blond hair has less melanin than someone with black hair. Also, people lose the melanin in their hair as they age. Is that why my grampy, Jebadiah Nurb, has all white hair? Exactly. Hair also comes in different textures, like curly, straight, and wavy. And bald, which is beautiful. Oh my goodness! Chloe look! The beans I threw, they worked! It's a magical, fantastical, hairy bean stock. Woo hoo hoo! Nurb, it's hair. It doesn't need beans to grow. The average hair grows half an inch per month. And some people can grow the hair really long, down their backs, or even longer. Oh yeah? Well, if it doesn't need beans to grow why does it look so healthy and magical? It's not magic, Nurb. Washing hair regularly helps keep it looking great. Wash it and it looks great. Ha! A likely story. Well, it helps to brush and comb it regularly too. And eat healthy food. A nutritious diet keeps your body healthy from the inside out. Well I'll be Nurb. I guess you're right. It is a huge, healthy hair. No beans needed. Glad to see you've come around. Now let's climb it and get a better view. Wow. I can even see my mommy's house. Yo, Ma! What's for lunch?