SCIENCE PARTS OF SENSE ORGANS IN GRADE THREE

SENSE ORGANS

1. cornea - like a clear glass that covers the front of the eye. sclera - t he white part of the eyeball and has the important job of covering most of the eyeball. iris - is the colored part of the eye. It lets the right amount of light to enter the eye. pupil - the center of the iris The is a circular hole where light enters. lens - focuses the image we see onto the retina located at the back of the eye r etina - is like a “screen” where the image of the object seen is focused. optic nerve - connected to the eye sends the message to the brain to tell about the image seen.

2. OUTER EAR pinna - he outside of the ear. This is the part that you can see where the girl’s earring is pierced.It collects sound and directs it into the ear canal. ear canal - is like a tube where ear wax is formed. It directs the sound into the eardrum. earwax- protects the ears eardrum is like a thin piece of skin stretched tight like a drum. When sounds reach the eardrum, it shakes or vibrates. three small bones connected behind the eardrum: hammer , anvil , and stirrup . INNER EAR cochlea - is the snail-like part which is filled with liquid. When it vibrates, it sends messages to our brain through the auditory nerve to tell us about the sounds we hear. semicircular canals - These canals help maintain your balance.

3. nostrils - are the two holes of the nose. Inside the nostrils are hairs that Nasal cavity - is the space behind your nose, in the middle of your face. Olfactory nerves - It send messages to the brain which interprets what we have smelled.

4. taste buds - are special structures that help detect taste. papillae - bumps of the tongue which contains the taste buds, and nerve endings. The four common tastes are sweet, sour, bitter, and salty. nerves - send messages to the brain which interprets the taste of the f ood .

5. EPIDERMIS - i s the outer layer of the skin on the surface on which dead skin cells are found. This is the part that we can see and touch. It melanin - is responsible for your skin color pores – tiny openings where sweat is released DERMIS is the inner layer of the skin which contains blood vessels, nerves, sweat glands, and oil glands. Sweat glands secrete sweat or perspiration. Oil glands produce an oily substance called sebum . This is the skin’s natural lubricant. HYPODERMIS or lower dermis is sometimes called the subcutaneous layer . It is made up mostly of fat that keeps the body warm and absorbs shocks.