Th e Fi ve Se ns es

The Sense of Touch =

The skin allows us to have the sense of touch =

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 layer 1.made mostly of fat 2.helps your body stay warm 3.absorb shocks 4.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. Hair Nerves 7. Blood Vessels 8. Fat Cells 9.

Th e Se ns e of Ta ste What parts of the body give us our sense of taste? Tongue BrainNose

The Tongue - Tongue is the sense organ that detects flavor. many grooves on the surface - Inside the grooves there are many taste buds which are taste receptors.

Magnified taste bud Papillae Microscopic view of taste buds (x100) brain food sensory cell

What are the three functions of the tongue? Th e Se ns e of Ta ste Ea t 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.

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 chemicals in 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

Areas of Taste on the Tongue Th e Se nse of Tas te

Th e Se ns e of S me ll What parts of the body give us our sense of Smell? NoseBrain

How do we smell ? -Nose is the sense organ that detects smell. -There are millions of smell receptors inside our nose. nasal cavity

What are the functions of the Nose? Smell BreatheTaste The Sense of Smel l

Magnify chemicals in 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 away the 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.

The Sense of Hearing What parts of the body give us our sense of Hearing? EarBrain

What are the functions of the Ear? HearingBalance The Sense of Hearing

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 brain Auditory Nerve

How does it all work? 1.____________________ are collected in the outer ear. 1.Sound waves pass through our _________________ and cause our ear drum to vibrate. 1.These _________________________ are sent to our inner ear by the ossicles. (small bones in the middle ear) 1.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. 1.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. 1.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

The Sense of Sight What parts of the body give us our sense of Sight? Eye Brain

What is the function of the Eye? Sight The Sense of 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. 1.Light then enters through the outer part of the eye, called the ___________________. 1.Next, light rays go through an opening called the _____________. 1.Light passes through the lens on its way to the back of the eye. 1.The retina sees the world upside down, but the ___________ turns it right side up. 1.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. 1.____________________ someone can see stuff that's near, like a book, but has trouble seeing stuff that's far away. 1.____________________ someone can see stuff that's far away, but has trouble seeing up close, like reading the print in a book. 1.____________________ 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 TV 1.staring for a long time — can strain your eyes. 5.Never share eye glasses or eye care products ophthalmologist