Fun Science: The Human Body
Professor Gizmo (Amazing Science Presentations) gives expert video advice on: What is my body made of?; Why do we get "goose bumps"?; How do I catch colds? and more...
What is my body made of?
My body is made up of atoms, and these atoms work together to form molecules, and these molecules work together to form organelles, and these organelles work together to form organs. All of these organs work together to form us; the full organism. So our body is made up of basically chemicals, and how they all interact together makes us who we are.
Why do we get "goose bumps"?
Goose bumps are a little leftover thing from our ancestry. If you look at your arm, there's hair on it. When you get a goose bump, the hair actually stands up on a goose bump. And what the goose bump was designed to do was to stand up, and when the hair stands up, it creates a layer of trapped air on our body and keeps us warm. So, when we are chilled we'll get a goose bump and our body is usually reacting to the cold, and trying to insulate us by having our hair stand up on end, trap the air, and trapped air makes a good insulator, and keeps us warm.
Why do I get "brain freeze" when I eat ice cream?
Well, when you get a brain freeze and you're eating ice cream, boy doesn't that hurt? What's actually happening is you're freezing the lower part of the brain behind your throat, and that seems like it's a very painful sensation.
Why does my skin look like a "wrinkled prune" after I take a bath?
Your skin will look like a wrinkled prune after taking a bath, because our skin is composed of layers. There is the outer layer which is basically dead skin, and that is the part of the body that is exposed to the air and everything around us. And then below that is the living layer of the skin and when you get into water that outer layer absorbs water. And, because you have two layers right next to each other, one layer is going to cause the other layer to pull and causes all these wrinkles and bumps in the skin so the longer you are in the water, the more water your outer layer will absorb and that causes the skin to wrinkle.
Why do I sweat?
You sweat because you're warm, and this sweating is actually your body putting a layer of liquid on the surface of the skin. And that layer of liquid is then exposed to the air and it evaporates. Now evaporation is a cooling process. It actually needs the heat energy from our body to evaporate, so as it evaporates it's taking the heat from our body, and because it's taking the heat from our body, the evaporating water in our skin, or sweat, actually cools our body down so we're not so uncomfortable.
How do I my eyes see color?
How do we see colors? Our eyes are set up so that we have receptors in the back of our eyeballs and some of these receive color signals and some of these receive black and white signals. Now. When at night, I don't know if you've ever noticed this, but at night when you're looking around in a dark area, there's no color. Everything is black and white. But yet, everything has color, but there's not enough light energy there to stimulate the color receptors in our eye. So that when you see things at dark, at dusk, everything seems black and white. If you turn the lights on and you're in a room that's dark, you're going to see black and white first, you turn the lights on, you're going to see bright vivid colors. So our eyes are meant so that we can see in the night with black and white and in the daytime with color. Now, it's good that we have the black and white vision at night because that's actually more sensitive. You can see much more things at night with our black and white vision than you can with color. And another interesting thing, at night if you're looking at stars, if you see a star in the sky, you're best not to look directly at it because if you look directly at it, it's hitting the blind spot in the back of your eye. If you're looking at something in the night sky, look a little bit away from it and just get an angle view at it and you'll see it brighter and you'll see it better.
What happens to food when I eat it?
When you eat food it will be first of all taken into your mouth. In your mouth will go through kind of like basically called mechanical digestion where your teeth and tongue will grind the food up into smaller particles. And gets into the stomach and in the stomach it starts breaking down the ground up food from your mouth even further we are break it down into chemical size pieces of food so that can be absorbed into the body through the stomach, through the intestine, and its mainly through the small intestine and these particles are then absorbed into the small intestine and the food is then distributed through out the body by the blood stream.
Why do I need food?
We need food for energy. We can't just go on without any form of energy, and we can't lay out in the sun and get solar energy; so we have to take in food. Food is basically, if you stop and think about it; stored solar energy. This is because every piece of food that you eat, you can trace it back to energy from the sun. So basically stored solar energy gets into our body, and our body through the digestive system breaks it down into small enough particles that can be taken to the cells. These cells have the ability then to release that energy and keep us warm, help us move and give us energy.
How do I catch colds?
Colds are basically caught from a virus. A virus that produces the cold will probably be in the air that you breathe, or it might be on somebody. So if you get that virus into your body, either through your nose or your mouth or even through your eyes, that virus will then get into your body and cause your body to have the cold. Then when you have these viruses on you, you can transfer that cold onto somebody else.
What is the difference between a virus and a bacteria?
If somebody that has a cold is near you, and they either cough some of the virus into the air, or you touch somebody and then you touch your mouth, or you rub your eye; the virus can get into your body. And once the virus is in your body, it's goning to affect the cells in your body, and the actual virus uses your cells in your body to make more viruses. When those viruses are released from you through coughing or from drinking water or something, you're going to send this virus out and somebody else may pick that virus up. Whereas a bacteria doesn't get into the cells and they use the cells for a place to reproduce. Viruses are really hard for our bodies to fight. There isn't a medication that we can take to fight a virus. But a bacteria, there are medications out there that will actually kill the bacteria. But we have a very hard time killing a virus. Our body basically has to fight the virus off itself.
Why does my tongue get stuck on metal in the winter?
In winter in cold climates, the metals get so cold that if you have any moisture on your lips or on your tongue or even on your fingers and you touch that metal that's that cold, the water actually freezes. Now, I had this happen to me when I was young. I was going down a hill on my sled. I got to the bottom. I was just kind of laying there, enjoying the wonderful winter day. And my lip was wet, and I put it down, rested my head on the sled, and it hit the metal part of the sled, and it froze there. I lifted my head up and it ripped, and I was bleeding. And it's only because the metal was so cold that my moisture on my lips caused it to freeze and when I moved away it ripped the skin.
What do I do if my tongue gets stuck on cold metal?
Well the best thing to do is wait for either the metal to warm up, and the water that's there to melt so that you get it off, or you're going to have to wait for someone to come and help you, and they can help warm up that metal. They can do that with warm water, but you have to make sure that that metal is not too big that the water freezes. Or, you just have to warm up the metal and move your skin away slowly. You don't want to move away quickly because that is when you have problems and you bleed.
Why do my cheeks turn red when I am embarrassed?
Basically, your cheeks turn red when you are embarrassed is the blood vessels. It could be your whole face. Some people just blush and their whole face turns red. But the blood vessels near the surface of the skin will open up. It's just a response that we have to like an embarrassment because our bodies are set up for either fighting or getting away from a situation that is dangerous. Well an embarrassing situation is in that line and it causes our blood vessels to open up. Blood flows through them: makes the skin red and that's where our blush comes from.
Why do I sometimes remember my dreams, and other times I don't?
Sometimes you remember your dreams and sometimes you don't. A lot of people that are really into dreams, what they will do is they will immediately upon waking up they'll write down their dreams because it really is hard to remember your dreams. The dreams that we are going to remember are usually the last ones that we have and sometimes the ones from some of the deepest sleep which is called REM (rapid eye movement). You can see when somebody is in that state because their eyes are closed but you will see the eyes moving around underneath their eyelids. And this is the type of sleep that will produce the dreams, and the only way to really remember them is immediately upon waking up that you write the dreams down and then you can remember them. Otherwise, they will pass through your memory very quickly.