understanding the w orld

Understanding the World Grade III ScienceMelissa R. Sison

School of Teacher EducationSaint Louis University

Baguio City

The Five Senses• Sense of Sight• Sense of Hearing• Sense of Smell• Sense of Taste• Sense of Touch

The Sense Organs and the Brain

The sense organs relay to the brain what is happening outside the body. The brain interprets what the sense organ’s message is all about.

What is this

smell?

Scent of a flower (rose)

Nerves carry signals to the brain

Nerves carry signals from

the brain

Brain interprets

the signals

Sense of Sight

The eyes are the organ for seeing.

Parts of the Eye

Image

Blood VesselsRetina

Optic Nerve PupilCornea

IrisLens

Functions of the Parts of the Eye

• Pupil- the pigmented part of the eye which regulates the amount of light that enters the eye.

• Lens- crystalline and transparent.- gathers and collect light from an object.

Functions of the Parts of the Eye

• Iris – colored part of the eye surrounding the pupil.

• Cornea – the glassy and bulging part where light is refracted as it passes through.

Functions of the Parts of the Eye

• Retina - back surface of the eye where image is formed.

• Optic nerve – connects the eye to the brain.

Common Ailments

• StyA swelling on the eyelid caused by infection.

• Sore eyeEyes become reddish and painful.There is also fluid discharge coming out of the eye.

Taking Care of the Eyes• Read with enough light.

• Use clean handkerchief to wipe your eyes. Do not rub it with your hands.

• Use sunglasses when the sunlight is too bright.

Taking Care of the Eyes• Avoid reading inside a

moving vehicle.

• Be careful in handling pointed objects.

Sense of smell

The nose is the organ for smelling.

Parts of the NoseOlfactory Cells

Olfactory nerve

Nasal cavity

Nostrils

Sinus

Functions of the Parts of the Nose

• Nostrils- opening of the nose where air enters.

• Nasal cavity - warms and moistens the air you breathe in.

• Cilia- fine hairs covering the nasal cavity which filter the air that enters the nose.

Functions of the Parts of the Nose

• Sinus- air spaces in the bones around the nose.

• Olfactory cells- differentiate one smell from the other

• Olfactory Nerve- connects and send signals from the nose

to the brain.

Common Ailments• Rhinitis- a swelling on the

nasal cavity caused by allergy, pollutants, drugs

or other diseases.• Sinusitis- inflammation of

the sinuses caused by infection.

Common Ailments• Colds- a viral infection

caused by rhinovirus usually affecting the nose and throat.

Taking care of the Nose

• Cover your nose in dusty places.

• Keep foreign objects away from the nose.

Taking Care of the Nose

• Blow your nose gently when you have colds.

• Clean your nose with clean, soft cloth.

Sense of Hearing

The ears are the organs for hearing.

Parts of the Ear

Outer ear canal

Pinna

Inner ear canal Eardrum

HammerAnvil

Stirrup

Eustachian tube

Cochlea

Auditory Nerve

Function of the Parts of the Ear

• Outer ear-collects sound waves and sends them to the

inner ear.• Pinna-it is the curved part of the ear attached to the head

• Ear Canal-directs sound waves to the eardrum.

Function of the Parts of the Ear

• Ossicles-consist of the three smallest bones in the body. Hammer, Anvil, Stirrup

• Inner Ear• Cochlea-contains the true organ

of hearing and balance.• Auditory Nerve-sends signals to

the brain.

Function of the Parts of the Ear

•Middle Ear-a hollow, air-filled cavity consisting of:

• Inner Auditory Canal- connects the outer ear to the middle ear.

• Eardrum-vibrates due to sound and sends sound waves deeper into the ear.

Common ailments• Otitis Media- infection of the

middle ear. A cold or some infection spreads to the middle ear and causes it to fill with fluid.

• Tinnitus-persistent ringing in the ear. It is caused by too much exposure to loud noises damaging the cochlea.

Common ailments• Deafness-loss of ability to hear

due to disease, drugs, trauma or inherent disorder.

Taking care of the Ear• Clean the outer ear with soft

cloth or cotton.• Keep water from entering the

inner parts of your ears when you swim or bathe.

• Keep pointed objects away from your ears.

Taking care of the Ear• Stay away from places where there are loud noises.

• Do not shout into your friend’s ears. Likewise, do not let them shout into your ears.

Sense of Taste

The tongue is the organ for tasting.

Parts of the TongueSour

Bitter

Sweet and Salty

Functions of the Tongue

• The tongue is usually flat, has no bones and its muscle fibers run to different directions so it is easily moved.

Common Ailments of the Tongue

• Inflammation of the tongue occurs when there is

infection, injury, deficiency in food that we eat, or if there is allergy.

•Spicy and hot food can also cause sore tongue.

Taking Care of the Tongue• Do not eat very hot, very spicy, or even very cold food.

• Brush the teeth and tongue regularly.• Use your own toothbrush. Do not borrow or lend your toothbrush.

Sense of Touch

The skin is the organ of touch.

Parts of the SkinEpidermis

Dermis

Hypodermis

Hair rootSweat GlandSebaceous G

land

Functions of the Parts of the Skin

• Epidermis-the top layer of the skin. It has a thin waterproof

covering made of dead cells. • Dermis-the thicker layer containing

nerve ending sensitive to cold, heat, pressure and pain

• Hypodermis-the thickest layer containing fat lobules.

Functions of the Parts of the Skin

• Sweat Gland-produces sweat, one of the by-products of our body.

• Hair root- part of the hair which is embedded in the

skin.• Sebaceous Gland-gives off oil to keep the skin from

drying.

Common Ailments of the Skin

•Tinea flava-appears as white spots on the skin especially on the face and arms.

Common Ailments of the Skin

•Scabies-caused by mites burrowing under the skin. It causes too much itching.

Common Ailments of the Skin

•Boils-hard, painful swelling on the skin caused by bacteria.

Caring for the Skin• Eat plenty of

fruits and vegetables.

• Take a bath regularly.

• Change dirty clothes.

Caring for the Skin•Drink plenty of water.

•Wash right away if the skin feels itchy.

•Do not over-expose yourself to sunlight.

«  All knowledge comes from

the senses. »- David Hume

Mr. Wilfred B. Bambico, PhDEducational Technology 2

School of Teacher EducationSaint Louis University

Baguio City