The Human Body and The Sense Organs
The head is supported by the head bone called the skull. The head houses the brain and the different sense organs.
Eyes – sense organs for seeing
Nose – sense organ for smelling. It is also used for breathing.
Tongue – located inside the mouth; sense organ for tasting. The Mouth is used for eating, talking, and at times for breathing too.
Ears – sense organs for hearing.
Hair – it covers and protects the head, grows on the skin called scalp.
The trunk is divided into two parts: the chest and abdomen.
The chest cavity is supported by the ribs. The chest protects two important organs of the body. These are the heart and lungs. The heart pumps blood to different parts of the body. The lungs get oxygen from the air we breathe in and give off carbon dioxide when we breathe out.
The abdomen houses and protects the stomach, the small intestine, the large intestine, and the other organs.
The stomach grinds the food we take in.
The small intestine changes this food to simple forms. Its walls are lined with fingerlike projection called villi, which help in absorbing the digested food.
The large intestine takes care of the undigested food. The undigested food is excreted through the rectum as stool or feces.
The kidney are used for the removal of liquid waste materials in the form of urine.
The eyes are our organs for seeing. The eyebrows, eyelashes, eyelids, and eye sockets protects the eyes.
The eyebrows protect the eyes from the dust and from seat that may roll down from the forehead.
The eyelids and eyelashes help prevent tiny particles from entering the eyes. When a tiny particle gets into the eye, the tear glands produce tears to wash it away. Blinking lays a film of tears over the eyes to keep them moist.
The light reflected by things around us passes through the cornea. The amount of light entering the eye is regulated or adjusted by the iris, which is the colored part of the eye.
The opening in the center of the eye is the pupil. It is a hole through which light enters the eye. The pupil changes shape as the iris changes shape.
At the back of the pupil is the lens, which functions like the lens of a camera. It focuses the object we are looking at on a screen called retina. The retina contains the nerve endings of the optic nerves. These nerves send a picture of what we see to the brain.
Taking care of the eyes
1. Eat food which contains vitamin A.
2. Rest if eyes are tired.
3. Avoid rubbing the eyes. If a tiny object enters the eye, try to wash it out by dipping your face in a basin of water and open and close your eyes while still in water. If the object cannot be washed out, see an eye doctor.
4. When reading, have enough light. Light should come from over the left shoulder. Avoid reading in moving vehicles.
5. If you have sore eyes, see a doctor for proper treatment. Stay home to prevent the germs from spreading to others.
6. Avoid looking directly at strong or glaring light, and never stare at the sun. Wear sunglasses to shield the eyes from the harmful glare of the sun.
7. Avoid putting sharp objects near the eye.
8. See an eye doctor regularly for a check-up.
The ear is our sense in hearing. We have the outer ear, middle ear, and inner ear.
The outer ear is shaped like a funnel. It catches sound waves. The sound waves pass through a canal which is lined with wax and hair that protect the inner parts of the ear. At the end of the canal is the eardrum, which vibrates to the movements of the sound waves. The vibration reachthe auditory nerves, which send a message of what the ear hears to the brain.
Taking care of the ears
1. Avoid shouting into the ear of another person. This may harm his eardrum.
2. Use a cotton swab for cleaning the ears. Hardened wax may be removed by a nurse or a doctor.
3. Never strike a person’s ear.
4. Blow your nose gently.
5. When swimming, be careful that no water gets into your ears.
6. See a doctor for ear infection.
The tongue is our sense organ for taste.
We identify food as sweet, sour, salty, bitter, pungent or hot, and a flat or tasteless.
Along the sides of the tongue are the taste buds. The taste buds have nerve endings that bring a message of the taste to the brain.
There are four areas of taste in the tongue.
The taste buds at the tip of the tongue taste sweet foods.
Those at the side taste sour and salty foods.
At the base are the taste buds which taste bitter foods.
Taking care of the mouth where the tongue is.
1. Brush your teeth after each meal regularly. Eating juicy, fresh fruits after each meal aids in cleaning the teeth.
2. Avoid taking in any food or liquid that is too hot or too cold.
3. Avoid putting in your mouth things other than your food, your spoon and fork, and your medicine.
4. A mouthwash helps keep the mouth parts healthy and clean.
The nose is our sense organ in smelling.
We smell object, we say that they are sweet, sour, bitter, pungent, or odorless. We also say some are foul smelling and others are fragrant.
How do we smell odors? Some things give off gases that mix with the air we breathe in through our nostrils. This air passes over the mucous membrane and reaches the olfactory nerves in the nose. These nerves carry the message of the odor smelled by the nose to the brain. The brain interprets the message.
The sense of a smell and of taste work closely together. Any food has a smell and a taste. The message from the tongue and from the nose come together to give the flavor of a particular food.
Taking care of the nose
1. Blow your nose gently. Cover your nose and mouth when you cough or sneeze.
2. Don’t stick seeds, cotton, or pellets I your nostrils.
The skin is our organ of touch. We learn about texture, temperature, and sensations of pain and weight with our skin.
The epidermis or outer layer protects the inner layer from injury and from the entrance of germs.
The dermis is the inner layer of the skin. It is made up of cells which contain blood vessels and nerves, sweat glands, and oil glands. The oil glands keep the hair and skin soft and moist.
The skin also regulates body temperature. Perspiration comes out of the skin.
Taking care of the skin
1. Take a bath regularly.
2. Use mild soap in bathing.
3. Change your clothes when they are wet with perspiration.
4. Do not scratch insect bites.
5. Have enough sleep, rest, and exercise.