Are bones hard as a rock?

Yes and no. Bones are hard connective tissue, made up of bone cells, fat cells, and blood vessels, as well as nonliving materials, including water and minerals. Some bones have a very hard, heavy outer layer made out of compact bone. Under this layer is a lighter layer called spongy bone, which is located inside the end, or head, of a long bone.

Spongy bone is tough and hard, but light, because it has lots of irregularly-shaped sheets and spikes of bone (called trabeculae) that make it porous (full of tiny holes). The soft, jelly-like inner core of bone is called the bone marrow. It is where red blood cells, certain white blood cells, and blood platelets are formed. The jawbone is the hardest bone in your body. Although bones are hard, they are not the hardest substance in the human body: the enamel on your teeth is harder.

Why does the body need vitamins and minerals?

Vitamins are chemicals that the body needs to function well; minerals are metals and salts that the body also needs in tiny amounts to run properly. Both help the human body grow. Different foods, like vegetables, contain different amounts of vitamins and minerals, so it is important to have variety in your diet so you can get a good balance. When it comes to vitamins, each one works differently in your body. Vitamin D in milk helps your bones grow; vitamin A in carrots helps you see at night; vitamin C in oranges helps boost your immune system and helps your body heal if you get a wound; and the B vitamins in leafy green vegetables help your body make protein and energy.

And although some vitamins like A (which helps your eyesight) and D are stored in your body (for several days or up to several months), others, like C and the B vitamins, quickly pass through your bloodstream. So it’s important to replace your vitamins every day.

What do eyelashes do?

Eyelashes protect our eyes. They help keep small particles and dust out of our eyes, especially when the wind is blowing. Eyelashes are also super-sensitive, and they alert the eyelids to shut when something touches them. If you rub your finger against your eyelashes, you will find that your eyelid automatically shuts.

But be careful not to rub too hard—if you lose a lash it will take about four to eight weeks to grow back! Fortunately, your upper eyelid has between 100 and 150 lashes.

Interesting facts about Eye

1.    We should never put anything in or near our eyes, unless we have a reason to use eye drops. We would only do that if our doctor or parent told us to use them.
2.    If the lens in our eye doesn’t work quite right, we can get glasses to help us see. Glasses have lenses in them that work with our eye’s own lens to help us see better.
3.    Just behind the pupil is a lens. It is round and flat. It is thicker toward the middle.
4.    Over the front of our eye is a clear covering called the “conjunctiva.”
5.    Blinking helps to wash tears over our eyeballs. That keeps them clean and moist. Also, if something is about to hit our eye, we will blink automatically.
6.    Some people start to sneeze if they are exposed to sunlight or have a light shined into their eye.
7.    The highest recorded speed of a sneeze is 165 km per hour.
8.    Our eyes have many parts. The black part on the front of our eye is called the “pupil.” It is really a little hole that opens into the back part of our eyes.
9.    Our body has some natural protection for our eyes. Our eyelashes help to keep dirt out of our eyes. Our eyebrows are made to keep sweat from running into our eyes.
10.    The most common injury caused by cosmetics is to the eye by a mascara wand.
11.    It is impossible to sneeze with your eyes open.
12.    Around the pupil is a colored muscle called the “iris.” Our eyes may be BLUE, BROWN, GREEN, GRAY OR BLACK, because that is the color of the iris.
13.    Our eyes are very important to us, and we must protect them. We don’t want dirt, sand, splinters or even fingers to get in our eyes.
14.    The reason why your nose gets runny when you are crying is because the tears from the eyes drain into the nose.
15.    The space between your eyebrows is called the Glabella.

16.    The white part of our eye is called the “sclera.” At the front, the sclera becomes clear and is called the “cornea.”
17.    We don’t want our eyes to get scratched or poked. That could damage our sight!
18.    Babies’ eyes do not produce tears until the baby is approximately six to eight weeks old.
19.    Inside our eye, at the back, is a part called the “retina.” On the retina are cells called “rods” and “cones.” These rods and cones help us to see colors and light.
20.    Your eyes blinks over 10,000,000 times a year!
21.    The study of the iris of the eye is called iridology.
22.    The shark cornea has been used in eye surgery, since its cornea is similar to a human cornea.
23.    The number one cause of blindness in adults in the United States is diabetes.
24.    The eyeball of a human weighs approximately 28 grams.
25.    The eye of a human can distinguish 500 shades of the gray.
26.    The cornea is the only living tissue in the human body that does not contain any blood vessels.
27.    The conjunctiva is a membrane that covers the human eye.
28.    Sailors once thought that wearing a gold earring would improve their eyesight.
29.    Research has indicated that a tie that is on too tight cam increase the risk of glaucoma in men.
30.    People generally read 25% slower from a computer screen compared to paper.
31.    Men are able to read fine print better than women can.
32.    In the United States, approximately 25,000 eye injuries occur that result in the person becoming totally blind.
33.    All babies are colour blind when they are born.
34.    A human eyeball weighs an ounce.

Why do some people have freckles?

People with light skin and eyes are more likely to have freckles because they have less melanin, a chemical in the skin that protects it from sun damage by reflecting and absorbing ultraviolet (UV) rays. Instead of tanning, they freckle.

Some people’s freckles fade away almost completely in the winter, and then return in the summer, when the person is more likely to sunburn. Sunscreen can help protect everyone (freckled or not) from the Sun’s harmful rays.

Do I have to brush my teeth?

Absolutely! Strong, healthy teeth help you speak clearly, chew harder vegetables and meats, and help you look your best. Brushing your teeth helps prevent plaque, a clear film that sticks to your teeth. The sticky film acts like a magnet for bacteria and sugar. Bacteria eats the sugar on your teeth, breaking it down into acids that deteriorate tooth enamel, causing holes called cavities. Plaque also causes the gum disease gingivitis, which make your gums red, swollen, and sore. At around age six, you lose your baby teeth and a larger set of teeth begin to surface. Eventually, 32 new teeth will line your growing jaws, the last coming in around the age of 18.

These permanent teeth will perform all of your eating tasks for the rest of your life, so they are worth taking care of! Your four front teeth (on top and bottom) are sharp incisors that cut and tear off food when you bite, along with your four pointed canine teeth. The flat-topped bicuspids (premolars) and molars near the back of your mouth crush and chew your food.

Does the red color in fruit juice really come from a beetle?

Yes. The red coloring that makes many juices and jams red is from a natural dye called carmine. Carmine is derived from conchineal, or conchineal extract, Which comes from the bodies of a female beetle (Dactylopius coccus) that lives on the Opuntia cactus. The insect is boiled and the scales of the insect are crushed into a red powder.

It takes about 70,000 insects to make one pound of cochineal. The ancient Aztecs used cochineal as a dye for cloth and other items, and today it is widely used as a coloring agent for food, beverages, and cosmetics.

What do potato chips have to do with the heart?

Potato chips often contain saturated fats, which over time can clog the arteries that carry blood to the heart. The oils used to cook the chips are made up of saturated fats, which increases cholesterol production in the body, a known risk factor for heart disease.

Heart disease results from a condition known as atherosclerosis, which happens when a waxy substance forms inside the arteries that supply blood to your heart.

What is constipation?

Constipation occurs when your body has a hard time having a bowel movement, or going poop. When you digest your food, it collects in the last part of the colon, or the end of the large intestine. If the feces doesn’t have lot of fiber or bulk to it, it stays in the colon longer than it normally would.

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Water continues to draw out of the feces, making it hard and compact instead of squishy and moveable. The rectum has to push extra hard to get your poop out. Constipation usually resolves itself, but your body can avoid constipation by eating plenty of fresh fruit, vegetables, and bran, and drinking plenty of water each day.

How does an ear thermometer read body temperature?

An ear thermometer reads the spectrum of thermal radiation given off by the inner surfaces of a person’s ear. All objects give off thermal radiation (including the light emitted by a glowing incandescent light bulb) and that radiation is characteristic of their temperatures. The hotter an object is, the brighter its thermal radiation and the more that radiation shifts toward shorter wavelengths.

The thermal radiation from a person’s ear is in the invisible infrared portion of the light spectrum, which is why you can’t see people glow. But the ear thermometer can see this infrared light and it uses the light to determine the ear’s temperature. The thermometer’s thermal radiation sensor is very fast, so it can measure a person’s body temperature in just 168 a few minutes.