| Seeing | | | | balance. |
| - The part of your eye that gives it its color is | | | | Smelling |
| called the iris. It has lots of tiny muscles that open | | | | - There are about 10 million smell receptors up in |
| your pupil ( the round hole in the center) to let in | | | | the space behind your nose for detecting smells. |
| more light when it's dark, or make it smaller when | | | | Working together with you brain, this group of |
| it is very bright out. | | | | nerve cells is able to detect about 10,000 |
| - What film is to a camera, the retina is to your | | | | different odors. |
| eye. It has millions of two main nerve cells to | | | | Taste - You are born with about 10,000 taste |
| catch light. Rods - which are mostly around the | | | | buds, but this drops over time to about 5000 by |
| sides, are best at helping you to discriminate light | | | | the time you are old. Taste buds detect sweet, |
| and dark. Cones, which are near the center, are | | | | sour, salty and bitter. Tasting is about 80% smell, |
| for detecting color. Nerve cells from the retina | | | | and your sense of smell increases when you are |
| connect your eye to the parts of the brain that | | | | hungry. |
| process vision - the occipital lobes which are | | | | Touch |
| located in the back of your head. | | | | - The skin is the largest organ in the body, |
| - Like your fingerprints, irises and retinas are | | | | weighing in at about 6 - 10 lb. Your skin detects |
| individual. | | | | touch via receptors for pain, pressure and |
| Hearing | | | | movement, cold and heat. |
| - The three smallest bones in the body - named | | | | - Most touch receptors are for pain. Skin is least |
| the hammer,the anvil and the stirrup (the smallest, | | | | sensitive in the middle of your back, and most |
| at about 3 millimeters) pass sound from your | | | | sensitive in hands, fingertips, and lips |
| eardrum to your inner ear. | | | | Hopefully this is enough to whet your appetite for |
| - The inner ear has special nerve cells to pass | | | | fun and fascinating facts about the amazing |
| sound information for processing by the brain, but | | | | human body. Keep learning. |
| part of the inner ear helps you to keep your | | | | |