The Sense of Touch

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The skin allows us to have the sense of touch

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Protects the body from infection,

injury, and water loss.

•helps us regulate body temperature through perspiration.

•Without the nerve cells in our skin, we couldn't feel warmth, cold, or other sensations.

•Sweat- Cools off the body

•Goosebumps- keep the heat in.

The nerve endings in your skin can tell you if something is hot, cold, smooth or rough . They can also feel if something is hurting you. Your body has about twenty different types of nerve endings that all send messages to your brain.

•outer layer of our skin,

•It is the tough, protective outer layer.

•It is about as thick as a sheet of paper over most parts of the body.

•Constantly flaking off and being renewed

Middle layer of skin

The dermis contains….

1.Nerve endings-how things

feel

2.Blood vessels- carry blood

3.Oil glands- Produce Sebum

4.Sweat glands- produce sweat

Bottom layer1. made mostly of fat 2. helps your body stay warm3. absorb shocks4. Each hair on your body grows out of

a tiny tube in the skin called a follicle

5. Every follicle has its roots way down in the subcutaneous layer and continues up through the dermis.

The Skin

1. Epidermis

2. Dermis

3. Subcutaneous

5. Sweat Gland

4. Oil Gland

6. HairNerves 7.

Blood Vessels 8.

Fat Cells 9.

Tongue

Brain Nose

The Tongue

- Tongue is the sense organ that detects flavor.

- Inside the grooves there are many taste buds which are taste receptors.

Magnified

tastebud

Papillae

Microscopic view oftaste buds (x100)

brain

food

sensory cell

Eat

Speech Taste

The tongue moves and pushes a

small bit of food along with

saliva into your esophagus,

which is a food pipe that leads

from your throat to your

stomach.

• The top of your tongue is covered with a layer of

bumps called papillae

• . Papillae help grip food and move it around while

you chew.

• They contain your taste buds, so you can taste

everything.

file://localhost/Volumes/USB DISK/5th Grade/Health/The senses/Swallowing.MOVfile://localhost/Volumes/USB DISK/5th Grade/Health/The senses/Swallowing.MOV

Process to taste food

- Flavoring chemicals in food dissolve in the

saliva

- Stimulates the taste buds to send messages

to the brain.

- Messages are sent to the brain to give us the

taste of the food

chemicalsin food

sensory cell

- Humans have four kinds of taste buds.

- They can detect four kinds of tastes:

sweet, sour, salty and bitter.

- Each kind of taste buds is not evenly distributed on the tongue.

Thus, certain parts of the tongue are

more sensitive to a particular taste

than the others.

sweet

bitter

sour

salty

Nose Brain

How do we smell ?

- Nose is the sense organ that detects smell.

- There are millions of smell receptors inside

our nose.

nasal cavity

Smell

Breathe Taste

Magnify

chemicalsin food

nasal cavity

nerve

Brain

sensory cell

mucus lining

inside

Process to smell food

- When we breathe, some chemicals enter our

nose

=> chemicals dissolve in the mucus

=> stimulate the smell receptors to produce

messages

=> These messages are sent to the brain to

give us the odor of the food.

Some chemicals in the food diffuse into the air.

We use both smell and taste to detect the flavor of food.

Holding your nose can help take away unpleasant taste of food.

Why do warm foods have stronger flavor than cold foods?

This is because when food is heated, more chemicals in food diffuse into the air.

Some medicine is unpleasant to take. You can hold your nose while taking the medicine. This helps take awaythe unpleasant feeling.

Our tongue can only distinguish about 4 different tastes. But our nose can distinguish about 4000 different chemicals.

Thus, when our nose is also used to sense the food, the food ‘tastes’ better.Our nose can tell us not only the sweet

taste of ice-cream, but also whether it is chocolate flavour or not.

Why do the elders like to take in food with strong flavor?

It’s too salty!

This is because the senses of smell and taste of

the elders are weaker.

Food with strong flavor tastes good to the elders.

Ear Brain

HearingBalance

Structures of the ear

The OUTER EAR

________________: (pinna) Collects sound waves

________________: sound waves pass through to the ear drum.

Ear Lobe

Ear Canal

Structures of the ear

Ear Drum

Ossicles

The MIDDLE EAR

________________: thin membrane that vibrates( stretched across the ear canal)

________________: three small bones which help carry the sound waves (hammer, anvil, and stirrup)

Structures of the ear

Cochlea

Semicircular Canal

The Inner EAR

________________: coiled tube in the inner ear (snail shaped) filled with liquid and hair like cells.

________________: three small tubes in the inner ear which control your balance

________________: carries impulses from the ear to the brainAuditory Nerve

How does it all work?

1. ____________________ are collected in the outer ear.

2. Sound waves pass through our _________________ and cause our ear drum to vibrate.

3. These _________________________ are sent to our inner ear by the ossicles. (small bones in the middle ear)

4. The vibrations reach the ______________________. The fluid in the cochlea begins to move, this motion results in the hair cells sending a signal along the auditory nerve to the brain.

5. Our __________________ receives these impulses and interprets them as a type of sound.

Sound Waves

Ear Canal

Vibrations

Brain

Cochlea

Ear Problems

1. ____________________ in the middle ear are the most common ear problems. Germs from colds in the nose or throat can spread through the Eustachian tube in the middle and inner ear.

2. Hearing loss and deafness- This can result from injury, disease, birth defects, and very loud noises.

• ___________________________: is someone who is specially trained to test and help with the problems related to hearing loss.

Audiologist

Infections

Eye Brain

Sight

Structures of the eye

Cornea

Iris

Cornea

Optic Nerve________________: Transparent coating which covers the iris and the pupil at the front of the eye.

________________: The colored part of the eye that regulates the amount of light entering the eye.

Structures of the eye

Pupil

Lens

________________: The opening at the center of the iris.(hole)

________________: A clear part of the eye behind the iris that helps to focus light, or an image on the retina

Optic Nerve

Cornea

Optic Nerve

________________: The light-sensitive tissue lining at the back of the eye. The retina converts light into electrical impulses that are sent to the brain through the optic nerve)

________________: A bundle of more than one million nerve fibers that carries visual messages from the retina to the brain.

Optic Nerve

Structures of the eye

Retina

Optic Nerve

Cornea

How does it all work?

1. ____________________ bounce off an object you are looking at.

2. Light then enters through the outer part of the eye, called the ___________________.

3. Next, light rays go through an opening called the _____________.

4. Light passes through the lens on its way to the back of the eye.

5. The retina sees the world upside down, but the ___________ turns it right side up.

6. When you look at an object, each eye sees a slightly different picture. The brain combines the images into one picture.

Light Rays

Cornea

Pupil

Brain

Eye Problems

1. ____________________ It can cause redness, itching, inflammation or swelling, and a clear or white, yellow, or greenish gooey liquid to collect in the eyes.

2. ____________________ someone can see stuff that's near, like a book, but has trouble seeing stuff that's far away.

3. ____________________ someone can see stuff that's far away, but has trouble seeing up close, like reading the print in a book.

4. ____________________ A misshaped cornea or lens causing objects to look blurry

Pinkeye

Farsighted

Nearsighted

Astigmatism

Eye Care

1.Visiting an ____________________ (a medical doctor who specializes in examining, diagnosing, and treating eyes)at least every 2 years

2.Wearing sunglasses 3.Wearing protective eyewear whenever you play

sports 4.Take breaks from the computer, video games, or

watching TV1.staring for a long time — can strain your eyes.

5.Never share eye glasses or eye care products

ophthalmologist

Presented by: Dr. Raj SharmaThank yu