Interesting Facts About Eyes
|
Your eyes sit in a hollow space in the skull and are protected by eyelids, cheekbone and eyebrow bones.
What is the first thing you notice about someone's eyes? Get a mirror and look at yours.
- You will look through the cornea, which is the curved, transparent outer area.
- Next, you will see the iris. The iris is the area around the pupil in the center of the eye. The iris can vary in color depending upon your genes; you may have brown, blue, green or hazel. The iris is also the muscular part, which causes the pupil to change size.
- The pupil is the area through which light and images we see pass. The pupil changes size depending upon available light.
- Behind the pupil is something you cannot see--the lens. The lens is the part of the eye that bends rays of light and focuses images on the back of the eyeball. Muscles help change the shape of the lens. If you are looking close, the lens becomes thick. If you focus on something far away, the lens will become thinner.
- As light travels through the lens, it goes through a clear gel-like substance which makes up most of the eye. It is called Vitreous Humor.
- After going through the humor, we reach the back wall of the eye called the Retina.
Do you need glasses?
Sometimes the eyes don't focus images properly on the retina. Your eyeball can either be too long or too short. If your eyeball is too short then the image will fall behind the retina. If this is the case, you will be far sighted, because your eyes can see things clearly from far away but not close up. If your eyeball is too long the image will fall in front of the retina and you will be nearsighted, because your eyes can see things close to you but not far away.
submitted by: Amy Hendrickson, Eastern NC AHEC, TeleHealth Program Coordinator 6-99
|
Interesting Facts About Hair
|
Hair covers every inch of your body except your lips, palms, and the soles of your feet. The hairs range from big like those on your head to small like those on the back of your hand, fingers, stomach, back, etc. The average adult has about 5 million hairs on their body-don't get excited-most of these you can hardly see.
- Hair is made up of Keratin, which is a body protein. Keratin is the same stuff that makes claws, hooves, feathers, antlers, and fingernails. Hair grows out of something called a follicle. A follicle is a very tiny opening in the skin, if your follicles are round- you will have straight hair, if they are oval, you will have curly hair.
- Hair color is determined by the same thing that determines skin color--melanin. Melanin is a chemical pigment. The more melanin you have in your hair, the darker it will be. If you have no melanin, your hair will be white. If you have some melanin, then your hair will be blond or strawberry, even more gives you red hair, then brown, then black.
- As you approach puberty, you will notice changes in your body such as changes in the patterns of body and facial hair. You will begin to develop under arm hair and pubic hair. Boys will begin to see facial hair and chest hair. Girls will notice that their leg hair is becoming darker and coarser.
submitted by: Amy Hendrickson, Eastern NC AHEC, TeleHealth Program Coordinator 6-99
|
Interesting Facts About The Circulatory System |
- Your heart is a hollow muscle about the size of your fist. It is located between your lungs, near the center of your body. If you weigh 100 pounds, you have a little less than one pound of heart muscle.
- Your heart pumps 8,000 gallons of blood through 12,000 miles of arteries, veins and capillaries everyday. It beats over 100,000 times per day. Your heart started beating 6 months before you were born. So, during an average lifetime, your heart will beat almost 3 billion times!
- The hearts squirts about 1/2 cup of blood through its valves on each heart beat. Between beats, the heart relaxes for about half a second. That is the only rest your heart ever gets! Blood makes about 1,000 complete trips abound your body each day. Each trip takes about 1 minute
- A 100-pound person has about seven pounds of blood which is enough to fill four quart-size milk cartons. Your blood has about 25 trillion red blood cells. Theses cells transport oxygen to your muscles, organs, bones and other tissue. About 8 million of your red blood cells die every second. But don't worry, they are quickly replaced by new ones.
- Each time your heart contracts, it forces blood out into the arteries. Arteries carry oxygenated blood away from the heart. ("ARTERIES--AWAY"). While the heart is resting after this contraction, the artery walls contract to push the blood along. Each time the artery walls expand and contract is one pulse beat.
- Body size, fitness level, and age affects a person's pulse rate (the number of pulse beats per minute.) Check out these different pulse rates in the animal kingdom:
| Resting Pulse Rate per Minute |
| Canary |
500 to 800 |
|
Dog |
70 to 120 |
| Mouse |
300 to 500 |
|
Human |
60 to 80 |
Chicken |
300 to 350 |
|
Lion |
40 to 50 |
| Cat |
120 to 140 |
|
Elephant |
25 to 50 |
(Do you think size makes a difference in how high pulse rates are?)
submitted by: Karen Vail-Smith, ECU Department of Health Education, 1-20-97
|
Interesting Facts About The Muscular System |
Whenever you move in any way (getting out of bed, kicking a football, brushing your teeth, even smiling) muscles are moving the bones and skin in your body to accomplish the movements.
- You have 600 muscles which work together in different combinations to allow you to move. You have over 100 muscles in your face which allow you to smile at a joke, eat a banana, or stick your tongue out at your little brother! If you don't want to overwork your face muscles remember that it takes 34 muscles to frown and only 13 to smile!
- How does this work? Pretend you're getting ready to take that game-winning free-throw shot. How do your arm muscles know how far to throw the basketball and in what direction to throw it? Enter: YOUR BRAIN! Your brain sends a chemical message along the nerves to the particular muscle fiber you want to move. These muscle fibers are long thin cells that lie along side each other. They look like spaghetti noodles in a box. These bundles of muscle fibers form the major MUSCLE GROUPS in your body. When your ready to take that shot, the brain will signal certain muscle fibers to contract. It between contracting, these fibers will relax. An individual muscle is only capable of contracting and relaxing. That's how muscles move!
- Some of the important muscle groups and their functions include:
| Shoulder Muscles: |
Raise the arms; helps you carry things. |
| Arm Muscles: |
Raise and lower the arms; bend the elbow joints. |
| Diaphragm Muscle: |
Allows you to breath, speak, laugh, cough, sneeze and hiccup! |
| Abdominal Muscles: |
Controls large trunk movements, enables you to have good posture. |
| Calf Muscle: |
Controls movement so the ankles, feet and toes |
| Thigh Muscles: |
Straightens and bends the knee joints, raises and lowers the legs, enables you to stand, walk, run, and climb. |
submitted by: Karen Vail-Smith, ECU Department of Health Education, 1-20-97
|
Interesting Facts About The Lungs |
About 21,600 times a day you take a breath. That means that you breath in through your nose or mouth, down into your trachea (windpipe), through the branching bronchial tubes into the millions of alveoli (air sacs) in your lungs. Over the course an average lifetime, a person breaths 591,300,000 times. The lungs are one hardworking machine, huh??
- The lungs are bags of spongy tissue that hang on both sides of your chest cavity. Each lung has over 300 million tiny air sacs called alveoli. These air sacs are covered with tiny blood vessels and branch like grapes on a vine. While your lungs don't take up much room in your body because they are dense and compact, if you could spread all your lung tissue out flat, it would cover half of a tennis court.
- The function of the lungs is to take in blood carrying carbon dioxide and remove the carbon dioxide (when you exhale). The lungs then take in oxygen when you inhale and the blood. Your alveoli act as a swap shop for these gasses (carbon dioxide and oxygen).
- The number of breaths you take each minute is called your RESPIRATION RATE (breathing rate). This number various according to age, level of fitness and activity. The number decreases as you get older.
- Smoking can damage your lungs and here's how: When a person breathes in cigarette smoke, he or she breathes in hundreds of chemicals including tar, nicotine, hydrogen cyanide, and arsenic. Tar will remain inside the air passageways and paralyze the millions of tiny hairs (CILIA) that line your lungs and sweep out any dirt and germs that you breathe in. A single cigarette can stop cilia from moving for 20 minutes or more. Have you ever noticed that smokers cough more than the rest of us? That is because their cilia can't do its job because of the tar, so the smoker has to cough a lot to get the mucus and dirt out of his/her lungs.
Over a long period of time the tar and nicotine in cigarettes can scar and break the alveoli, leaving big air pockets. Breathing becomes more difficult and eventually these long-term smokers will develop a disease called EMPHYSEMA. People who develop severe emphysema can't lead normal lives. They often have to spend their last years in bed unable to take in enough oxygen in their lungs to even walk across the room!
If you would like to know what it feels like to have emphysema, try this. Use a small straw from the cafeteria. Put it in the center of your mouth and close your lips tightly around it. Pinch your nostrils together so you don't breathe out of your nose. What does it feel like to only have a tiny amount of air coming in? Do you have to breathe more often? Try walking around a little, but don't do this for too long!
submitted by: Karen Vail-Smith, ECU Department of Health Education, 1-20-97
|
Interesting Facts About The Stomach and Digestive System |
Your stomach is a hollow baglike organ which expands when you eat. Adult stomach are about the size of two fists and are eight inches from top to bottom and four inches across. When you fill it with food it can stretch to become twice as long.
- Why does your stomach growl when you are hungry? It is lined with glands that go into action every three or four hours whether or not food is present. Just thinking about food can start the glands expelling digestive juices. These juice will gurgle and rumble (growl!) as your empty stomach churns away.
Your stomach makes about 21/2 quarts of these digestive fluids everyday. These juices are composed of water, hydrochloric acid, and an enzyme that breaks down proteins. This acid will actually kill some of the bacteria you swallow with your food.
- The stomach has a ring of muscles at the top end and the bottom end to regulate entering and exiting of food. Have you ever had pain in the top of your stomach? HEARTBURN happens when partially digested food backs up in the esophagus.
- When we swallow our food, we also swallow air. This air causes most of the gas in your stomach and intestinal tract. The best way to get rid of this air is to burp! Unfortunately, in our culture good manners prevent us from just burping whenever we feel like it. However, in some cultures it's actually considered good manners to burp at the table at the end of a good meal. A big burp let's the cook know that your really enjoyed the food! (I wouldn't try this at the dinner table at home!!)
- What about gas at the other end? Where does it come from? There are millions of bacteria that live in the intestines and many of these give you gas. Certain foods give you gas as well. For example, it is believed that baked beans contain two sugars that your stomach and small intestines have no enzymes to use in breaking them down. When these bean sugars move to the lower intestines, the intestinal bacteria feed on them and produce cases of carbon dioxide, hydrogen, and methane. These gasses make you feel uncomfortable and eventually escape. Gas is not usually expelled until three to seven hours after you eat the beans. Not all beans are created equal when it comes to gas potential. Which beans produce the greatest about of gas?
| Least Gas: |
garbanzo beans, lima beans, black-eyed peas |
| More Gas: |
small white beans, green peas and pinto beans |
| Most Gas: |
black beans, pink beans soybeans |
| Other Gassy Foods: |
bagels, cabbage, cauliflower, brussel sprouts, melons and onions |
- Your body has a 32-foot digestive track. Digestion usually begins in your mouth. Food then travels to your esophagus, to your stomach, and then to you small intestines. Whatever food that has not been digested passes into your large intestine (colon) and then out the anus. This trip usually takes a day and a half.
| Travel Time for Your Big Mac: |
| Mouth |
(1 to 2 minutes) |
| Esophagus |
(4-6 minutes) |
| Stomach |
(1 to 6 hours) |
| Small Intestines |
(2 to 9 hours) |
| Colon |
(1 to 3 days) |
- The large intestine (colon) is where water from the digestive juices get re-absorbed back into the body. The colon also stores feces. Although normal feces is made up mostly of water, it also contains bacteria (both live and dead) and undigested food like plant fibers, fruit skins, seeds and the old linings of the digestive tract.
submitted by: Karen Vail-Smith, ECU Department of Health Education, 1-20-97
|
