Questions+and+Answers

= Do you have a question for Discovery World =

Q. Does cracking knuckles cause arthritis? Aaron D.**A. Many things can cause arthritis (e.g. disease, age, genetics), but most doctors don't think that knuckle-cracking is a big player. That doesn't mean that you should just crack away, however. There is always the chance that you could stretch a ligament too far and actually hurt yourself; plus, knuckle-cracking can become a bad habit that grosses others out.**

Q. Why do people have weak ankles? Ashley Mo.**A. Weak ankles are usually because of loose ligaments. If your joint doesn't stay pulled together, the bones can slide over each other too much and that can cause things to become strained or even tear. Loose ligaments can be passed down in your family or might be the result of an injury. The more ligaments stretch, the more likely they are to stay that way, which is why people with weak ankles usually wear a brace.**

Q. Is it true that crackling your knuckles causes wrinkles? Faye W.
 * A. Wrinkles are usually caused by the skin becoming less stretchy. Since cracking knuckles deal with your joints, they probably aren't related. Joints seem to have so many wrinkles mostly because there's extra skin there because they move so much and so far.**

Q. If you break a bone, does a different bone form, or does the same bone come back together? Tyree M.
 * A. When a bone is broken, the body will always try to heal by bringing the pieces back together; a process that actually begins immediately after the bone breaks. While a bone is healing, the osteoblasts will create a protective bone shield around the fracture, which helps keep the area strong until the healing is finished. The more closely the bones are lined back up, the easier it will be for the body to heal. That's why it's important to have a doctor set the bone.**

Q.If you broke a bone at the age of 7, and a scar was left there, Why can you see the scar at the age of 30 if you get a completley new skeleton? Andrew W.
 * A. Remember that the bones don't break down all at once. When the osteoblasts are building up the bones, they're doing very small and thin sections at a time. If there is a deformity in the bone, like a dent, scar, or old fracture, that shape will often be copied into the new bone. Deeper and larger deformities will take longer to fully disappear.**

Q. What is the difference between a break and a sprain? When you sprain something, how is treating the sprain different from treating a broken bone? Gina W.
 * A. Breaks happen to bones, sprains happen to ligaments. A sprain is when a ligament (the tissue that connects one bone to another) becomes partially or completely torn. Many of the steps to treat a sprain are similar to treating a broken bone: don't put weight on it, use ice to keep down the swelling, visit a doctor (especially if it's not getting better), keep the joint from moving too much while it's healing. Crutches, splints, and slings are used to treat both broken bones and sprains. Sprains heal much, much faster than broken bones, but only if you let your body do its job. The more a person with a sprain uses an injured area before it's healed, the longer it will take to heal and it might make it worse.**

Q. If you were to break your Adams apple would you die right away or would you stop breathing? Marilene S.
 * A. The structure that we call an "Adam's Apple" is actually a piece of cartilage. One of its main functions is to help protect the trachea (windpipe) from accidental injury. If one were to crush this cartilage, there would be a danger of damaging or collapsing the trachea, which could keep someone from breathing.**

Q. One of my aunts lost her right eye a couple years ago. She has a fake eye in her right eye socket now, but what does her eye socket look like now sinse she doesn't have an eye in that eye socket anymore? Does her skull start to shape that eye socket out of her head sinse she doesn't need it anymore? Ashley Mo**.**
 * A. Since you know someone who has lost an eye, one way to answer your questions would be to explain to your aunt that you are studying the body and you're interested in knowing more about what happened to her.**


 * Typically when an eye is removed or lost, a surgeon places a plastic ball into the eye socket. This keeps the body from reshaping the socket and allows for the muscles that once controlled the eye to attach to something. Artificial eyes are similar to thick contact lenses that sit over these muscles and move when the muscles move. The area behind the artificial eye is usually a pink tissue the same as what sits behind your eyelids.**

Q. What happens to your taste buds on your tongue when you burn them? Ashley Mo.
 * A. When you burn your tongue, you've temporarily killed off those taste buds. Happily, the inside of your mouth is one of the fastest-healing areas in your body and within a day to a week (depends on how bad the burn is) everything is back to normal. Next time be sure to let your soup cool before you chug it.**

Q. Why do your bones get bigger? Ashley K.
 * A. Bones get bigger because the body tells them to. Chemicals within the body tell cells to divide and make copies of themselves. Sometimes these signals are slowly and evenly sent out, but other times the body quickly or unevenly releases the chemicals.**

Q. Why are our hairs so shiny when we look at them in the disecting microscopes? Ashley Mo.
 * A. Remember that our sebaceous glands release oil. These glands are connected to the hair follicle and thus will deposit oil on the hair as it is growing.**

Q. Why is there loose skin between your thumb and pointer finger? Nellie M.
 * A. Loose skin on the body is usually to allow for more movement. While it may seem worthless, if you stretch your hand out and then move your thumb backwards, you will find that the loose skin seems to disappear and other skin becomes loose instead.**

Q. When you lay on your ear, why can you hear your heart beat? Nellie M.
 * A. You're hearing the blood rush through the arteries inside your head. Our ears are designed to pick up sounds from the outside world, but you may have noticed that if you have a cold or your ears need to pop, it seems like you're able to hear your voice inside your head. Most of the time there's too many noises for us to focus on the sound of blood moving, but by laying on your ear, you're blocking out those other sounds.**

Q. Does your skin react to the type of material that is touching it in a temperature way. Like does your body get cooler or hotter when it touches a certain material? Ashley Mo.
 * A. Your skin helps your body to control its temperature. Touching materials can allow your body to transfer or absorb heat, so essentially that answer to your question is "yes". Some materials are better at allowing heat and moisture to pass through than others, which can affect how warm or cold you think you are. I know some people who can't wear socks during the summer because they tell me that if their feet are too warm, their whole body gets warm.**

Q. How are coughs formed in the body? Faye W.
 * A. A cough is the body's way of getting rid of something that is irritating the lungs or airways. The cells that line the airways in our body are covered in little hairs. The purpose of the hairs is to trap dust and to filter out the air we breathe. If the hairs trap enough stuff, the cells send a signal to the brain to have the lungs force out air, which usually pushes out all of the accumulated debris. We call this a cough.**

Q. Is it bad for the gums to be ripped? Faye W.
 * A. Gums are part of the tissue that holds your teeth in place. Sometimes we cut or tear our gums on food that we eat. Usually the gums will heal like any other tissue in your body, but if the damage is too severe, they won't. Unlike the inside of our mouths or our skin, we don't grow new gums.**

Q. Is there a difference between a pregnant womans heartbeat compared to a nonpregnant womans heartbeat? Gina W.
 * A. From what I have heard, there isn't always a noticeable difference for every pregnant woman. One thing that could cause a difference is that a growing baby can change the blood volume (how much blood is being pumped) in the mother. This could cause a pregnant woman's heart-rate to go much higher than it might have been when she wasn't pregnant.**

Q. Why is it that when you something bloody or inside the body you get weak in the knees?
 * A. Some people react strongly to certain images or descriptions. When our brains react strongly to something it sometimes causes a quick, temporary loss of voluntary muscle control. If you are standing, you are trying to control a lot of muscles at the same time. Even a split-second disturbance in your concentration can cause the muscles to relax, which you might call "getting weak in the knees." If you were sitting down, you wouldn't feel the same experience. A similar thing happens if you've ever been shocked or surprised and dropped something you were carrying.**

Q. Why do my hands swell up in the cold? Ashley Mo.
 * A. My hands usually shrink up a little when they're cold. Perhaps your body is trying to keep your hands from getting too cold by pushing extra fluid into the cells. Fluid can help to insulate from drastic temperature changes.**

Q. If a person who needs their blood pressure taken, left arm is gone, will the right arm come up with the same number? Dylan G.
 * A. There is usually a difference in blood pressure between the right and left arm. If one arm is missing, the number would probably not be the same as it had been before. Doctors know how much the difference should be, however, so an accurate number could still be achieved.**

Q. When the diaphram contracts and makes room in the ribs, why do the lungs fill the space without an other muscle causing it? Steven N.
 * A. Breathing is a lot more complicated than most people think. Here's an easy answer to your question, however: When the diaphragm lowers and the muscles between the ribs make the chest area bigger, the pressure inside the chest is lower than the outside air. Pressures always want to be the same, so air will try to push its way into the body. The only path that will let air in or out of the body is through the trachea and lungs. Your lungs fill the space because air pushes its way into them and fills them up until the pressure inside is the same as the pressure outside.**

Q. Why, and how do you get light headed? Ashley K.
 * A. Light-headedness is your body telling you that there's not as much blood flowing to the brain as there should be. This usually happens when you stand up too quickly or have been spinning around or other similar activities. There are little pressure sensors in the arteries in your neck that monitor the blood going to the brain. If you suddenly stand up, gravity sometimes momentarily pulls blood back into your torso. The drop in blood pressure causes you to feel light-headed. The reason it only lasts for a moment usually is that those pressure sensors tell the heart to beat faster for a few seconds to make sure that your blood pressure goes back up.**