grade3 sense organs

28
You and Your Body Sense Organs

Upload: jeandale-vargas

Post on 19-Jan-2017

26.892 views

Category:

Education


3 download

TRANSCRIPT

Page 1: Grade3 sense organs

You and Your Body

Sense Organs

Page 2: Grade3 sense organs

Your EYES• Your eyes are your organs for seeing.• Each part of the eye has a function. There

are parts that protect the eyes. – eyelids, the eyelashes and the eyebrows.

Page 3: Grade3 sense organs

The inside of the eye has other parts..

Page 4: Grade3 sense organs

HOW YOU SEE THINGS

Have you ever entered a dark room? Can you still see objects inside? Without light, you cannot see anything. You need light to see the things around you.

Page 5: Grade3 sense organs

When you look at an object, these things happen:

1. light coming from every point of the object enters your eye;2. the light passes through the lens of the eye;3. the lens bends this light;4. this light falls onto the retina;5. the light forms an upside-down image on the retina;6. light-sensitive cells in the retina produce signals;7. the signals travel through the optic nerve into the brain; and8. you see an upright object.

Page 6: Grade3 sense organs

COMMON EYE DISORDERS AND DISEASES

Nearsightedness - have long eyeballs or a cornea that is too curved. (Normal eyeballs are almost round.) the image of an object from afar falls in front of retina. Nearsighted people cannot clearly see far objects. They need to wear corrective eyeglasses to help them see far objects.

Page 7: Grade3 sense organs

Farsightedness - People suffering from farsightedness have short eyeballs or a cornea that is not curved enough. The image of any near object falls behind the retina. Farsighted people also cannot clearly see the objects close to them. Farsighted people also wear corrective eyeglasses to help them see nearby objects clearly.

Page 8: Grade3 sense organs

Astigmatism - is another eye disorder. People with astigmatism may see blurred or ghost images, whether near or far. Astigmatism is caused by a cornea that is abnormally round. The cornea of one suffering from astigmatism is similar to a football round. If you look at a football, you will see two curves – a steeper one and a flatter one. The two curves of the cornea bend light that enters the eye, forming two images on the retina. An astigmatic person sees an out-of-focus images.

Page 9: Grade3 sense organs

Eye Disorders• One common disease

is conjunctivitis, also known as sore eyes or pink eyes. It is caused by an infection of the conjunctiva.

Page 10: Grade3 sense organs

Another eye disease is called sty, also known as kuliti. It is an eye infection of one or more oil glands at the edge of the eyelid or under it. A harmful kind of microorganism causes this infection. Sty develops at the edge of an eyelid, around the base of an eyelash.

Page 11: Grade3 sense organs

Glaucoma is caused by the abnormal or high pressure of liquids on the eyes. It causes the eyeball to harden, making it difficult for the person to see. This affects mostly older people. Glaucoma can cause blindness if not treated. Although glaucoma happens more often to elderly people, young children like you should have a regular check-up too.

Page 12: Grade3 sense organs

• Cataract is the clouding of the lens of the eye.• Cataract is often seen as white spots on the lens of

the eye. A person who has cataract has very poor vision.

• He or she is overly sensitive to light. He or she also frequently changes eyeglasses or contact lens.

• The cause of cataract is unknown. But it is strongly linked to smoking, diabetes and exposure to sunlight.

• Cataract can be treated.

Page 13: Grade3 sense organs

TAKING CARE OF YOUR EYES

Your eyes are your windows to the world. They let you see the things around you. It is therefore important to take good care of them.– Eat food rich in vitamin A such as pechay, cabbage, squash, milk,

cheese, eggs. Good sources of vitamin A come from yellow food.– Always read with adequate amount of light to avoid eye strain.– Avoid the glare of direct, strong light.– When strong wind blow, protect your eyes to keep dust and dirt

from entering them.– Always wear sunglasses that offer maximum protection from the

sun’s ultraviolet rays (UV) rays.– Etc.

Page 14: Grade3 sense organs

YOUR EARSYou hear different sounds every. You hear sounds of people talking, birds chirping or dogs barking. You hear music over the radio. What sense organs do you use to hear the different sound around you?

Page 15: Grade3 sense organs

Your ears are your sense organs for hearing. It is composed of the outer ear, the middle ear and the inner ear. The outer ear collects sounds, while the middle ear conducts the sound to the inner ear. The inner ear has nerves that send the sound waves to the brain, which then interprets the sound.

Page 16: Grade3 sense organs

THE PARTS OF THE EAR• The outer ear is made up of the

auricle, the ear canal, and the eardrum. – The cup-shaped structures on the sides of your

head are the auricles. – The ear canal is a passageway for sound from

the auricle to the eardrum. – The eardrum separates the outer ear from the

middle ear. It moves to and fro (or vibrates) as it receives sound waves.

Page 17: Grade3 sense organs

• The middle ear is a hollow chamber filled with air. Inside the chamber are three little bones – hammer, anvil and stirrup – that are joined. When the eardrum vibrates, it sends the hammer vibrating. These vibrations are passed on to the anvil and the stirrup. These three bones amplify the sound vibrations and sends them into the inner ear.

Page 18: Grade3 sense organs

• The inner ear contains both your organs of hearings and of balance. Its main parts are the cochlea, the vestibule nerve, and the semicircular canals.

• The cochlean is a coiled tube. It is filled with liquid and contains nerve cells. These cells send the message it has received through vibrations to the auditory nerves, then to the brain. Your brain interprets the vibrations as specific sounds.

Page 19: Grade3 sense organs

• The organ of Corti is found inside the cochlea, it can be thought of as the body’s microphone. It has a membrane that contains thousands of hair cells. The hair cels are excited when there is sound. The membrane containing the hair cells tells you the pitch of the sound you are hearing. It tells you whether the sound is loud or soft.

Page 20: Grade3 sense organs

• The vestibular and the semicircular canals are your organs of balance. This means that your ears do more than just hearing. They keep you from falling while you are walking, standing and sitting.

Page 21: Grade3 sense organs
Page 22: Grade3 sense organs

COMMON EAR DISEASESThe ears can suffer from many diseases that can affect the auricle are erysipelas and seborrhoea. Erysipelas is caused by bacteria. Malfunctioning of the oil glands of the ear’s skin causes seborrhea. Both diseases cause swelling of the skin of the auricle or even the skin of the ear canal

Page 23: Grade3 sense organs

An inflammation of the middle ear is called otitis media (luga). One common cause of otitis media is the presence of bacteria or viruses in the eardrum. The build up of pus exerts pressure against the eardrum causing earache, swelling and redness. If left untreated, the inflammation can impair hearing.

Page 24: Grade3 sense organs

TAKING CARE OF YOUR EARS

• Do not use cotton swabs or metallic objects to clean your ear canal. Use a moist, soft cloth instead. Your ears have a self-cleaning mechanism. Fine hairs inside the ear canal constantly move wax and dead skin out of the canal.

• Always consult a doctor when you feel pain in your ear.

• Avoid continuous exposure to loud noise.

Page 25: Grade3 sense organs

• Do not use earphones or headphones to listen to music when you are about to sleep. You might fall asleep without turning them off. If this happens, your ears will be listening to a nonstop sound.

• When you have cold, blow your nose gently with your mouth open.

• When sleeping outdoors, plug your ears with cotton so insects won’t get into your ears.

• When swimming, use earplugs. These will prevent water, dirt and other foreign objects from getting into your ears.

Page 26: Grade3 sense organs

YOUR NOSE Your sense of smell is wonderful. Just by smelling, you know what food your mother is cooking in the kitchen, what flowers are around, or what cologne your friend is wearing. Your nose is made up of cartilage and bone material. People have different sizes and shapes of noses, but all noses are used for smelling. As you breathe in air through your nose, you can smell the odors that the air is carrying.

Page 27: Grade3 sense organs

PARTS OF NOSE• The nose has delicate parts that work together to allow you

to identify odors:– The nose has openings called nostrils. The air enters through

the nostrils to your nasal cavity– The nostrils are lined with short hairs called cilia that filter

dust mixed with the air. The nostrils are also lined with moist membranes. This membrane warms the air that enters the nostrils.

– The nostrils lead to a hollow portion called the nasal cavity. Approximately, 95% of the nasal cavity has nothing to do with smelling. Most of its area only cleans and warms the air we breathe in.

– In the upper portion of the nasal cavity are the olfactory nerves. They send nerve impulses about scents to the brain.

Page 28: Grade3 sense organs

COMMON NOSE DISEASES

• Common cold can be accompanied by frequent sneezing. It brings about a discharge from the nose called mucus. Consult a doctor if the common cold does not go away after several days. You might be experiencing an allergy called rhinitis.

• Rhinitis is an inflammation of the nasal mucosa. It is often due to allergic reactions to pollen, dust or other airborne substances. Sometimes, it is even mistaken for the common cold because they have similar symptoms. Rhinitis causes nasal congestion, which makes breathing difficult. There is also a watery discharge from the nose