What’s in the bag? Blind fold students What’s in the bag? Blind fold students or (take away other senses) and have or (take away other senses) and have them identify different objects. Explain them identify different objects. Explain that senses help us receive information that senses help us receive information about our surroundings (and more than about our surroundings (and more than one sense can be used)one sense can be used)

Also discuss the difficulty that comes Also discuss the difficulty that comes with loosing a sensewith loosing a sense

See which student can identify the most See which student can identify the most objectsobjects

The SensesThe Senses

Ch. 36.2Ch. 36.2

I. Use Your SensesI. Use Your Senses

A. Your body has 5 senses:A. Your body has 5 senses:

1. Sight1. Sight

2. Hearing2. Hearing

3. Touch3. Touch

4. Taste4. Taste

5.5. SmellSmell

I. Use Your SensesI. Use Your Senses

B. Senses are often linked B. Senses are often linked together in the braintogether in the brain

1. Chemicals from an 1. Chemicals from an orange stimulate sensory orange stimulate sensory neurons in your nose and neurons in your nose and you smell the citrus smellyou smell the citrus smell

I. Use Your SensesI. Use Your Senses

2. Chemicals from the 2. Chemicals from the orange stimulate the orange stimulate the sensory neurons of the sensory neurons of the tongue when you eat it so tongue when you eat it so you taste the flavor.you taste the flavor.3. Food doesn’t have much 3. Food doesn’t have much flavor with a stuffy nose flavor with a stuffy nose because you can’t smell itbecause you can’t smell it

II. TasteII. Taste

A. A. Taste BudsTaste Buds- The sensory - The sensory receptors on your tonguereceptors on your tongue

1. Young adults have appx. 1. Young adults have appx. 10,000 taste buds10,000 taste buds

2. The # of taste buds 2. The # of taste buds decreases over time and decreases over time and smells and tastes are dulledsmells and tastes are dulled

II. TasteII. Taste

B. Taste buds categoriesB. Taste buds categories

1. Salty1. Salty

2. Sour2. Sour

3. Bitter3. Bitter

4. Sweet 4. Sweet

5. The “Pill Spot?”5. The “Pill Spot?”

III. SightIII. Sight

A.A. Sight depends on light Sight depends on light energy reaching sensory energy reaching sensory receptors in the eye.receptors in the eye.

1. Light passes through the 1. Light passes through the corneacornea first first

a. The outside a. The outside window of window of the eyethe eye

III. SightIII. Sight

b. b. AstigmatismAstigmatism is is caused caused by an uneven by an uneven corneacornea

1) Special lenses 1) Special lenses are are needed to correct needed to correct itit

III. SightIII. Sight

2. Light passes through the 2. Light passes through the irisiris and into the and into the pupilpupil

a. The iris regulates a. The iris regulates the the size of the pupil and size of the pupil and how how much light enters much light enters

b. The iris also gives b. The iris also gives they eyes colorthey eyes color

III. SightIII. Sight

3. The light image is then 3. The light image is then focused by the focused by the lenslens on to on to the the retinaretina..

a. The image is a. The image is smaller smaller & up-side-down & & up-side-down &

backwardsbackwards

III. SightIII. Sight

b. When objects viewed are b. When objects viewed are distance the lens is flatdistance the lens is flat

c. When objects viewed are c. When objects viewed are near the lens becomes more near the lens becomes more roundedrounded

d. The lens is associated with d. The lens is associated with glaucoma (too much fluid)glaucoma (too much fluid)

III. SightIII. Sight

e. If the eyeball is naturally too e. If the eyeball is naturally too long or short, corrective lens long or short, corrective lens (glasses) may be needed(glasses) may be needed

1) Near sighted (long 1) Near sighted (long eyeball) = Concave eyeball) = Concave

LensLens

2) Farsighted (short 2) Farsighted (short eyeball) = Convex Lenseyeball) = Convex Lens

III. SightIII. Sight

4. The 4. The retinaretina contains the contains the conescones and and rodsrods

a. Cones are receptor a. Cones are receptor cells adapted for cells adapted for

sharp sharp vision in bright lightvision in bright light

b. Cones also detect b. Cones also detect colorcolor

III. SightIII. Sight

c. Rods are receptor cells c. Rods are receptor cells adapted to detect shape adapted to detect shape and movement in dim lightand movement in dim light

d. There is a place with no d. There is a place with no rods or cones called the rods or cones called the blind spotblind spot

1) Paper demo1) Paper demo

III. SightIII. Sight

e. Sensory neurons in the e. Sensory neurons in the retina form the retina form the optic nerveoptic nerve that carries the image to the that carries the image to the brainbrain

f. The brain interprets the f. The brain interprets the message, flips and rotates it message, flips and rotates it and responds (or not)and responds (or not)

IV. SOUNDIV. SOUND

A. 3 parts of the EarA. 3 parts of the Ear1. Outer Ear1. Outer Ear2. Middle Ear2. Middle Ear3. Inner Ear3. Inner Ear

B. Sound is caused by B. Sound is caused by vibrations in the air around it vibrations in the air around it (sound waves)(sound waves)

IV. SOUNDIV. SOUND

C. Outer EarC. Outer Ear

1. Sound waves are 1. Sound waves are captured by the cup shape captured by the cup shape of the ear (Pinnea)of the ear (Pinnea)

2. They travel through the 2. They travel through the ear canalear canal

IV. SOUNDIV. SOUND

C. Outer Ear (cont)C. Outer Ear (cont)

3. The sound waves strike 3. The sound waves strike the ear drum (the ear drum (tympanic tympanic membrane)membrane) and cause it to and cause it to vibratevibrate

IV. SOUNDIV. SOUND

D. Middle EarD. Middle Ear1. The vibrations then pass 1. The vibrations then pass to 3 small bones of the to 3 small bones of the middle ear:middle ear:

a. Malleusa. Malleusb. Incusb. Incusc. Stapesc. Stapes

IV. SOUNDIV. SOUND

D. Middle Ear (cont)D. Middle Ear (cont)

2. As the stapes vibrates, it 2. As the stapes vibrates, it causes the causes the oval windowoval window to to move back and forthmove back and forth

a. Oval window is the a. Oval window is the membrane between membrane between

the the middle and inner earmiddle and inner ear

IV. SOUNDIV. SOUND

E. Inner EarE. Inner Ear

1. The movement of the 1. The movement of the oval window causes the oval window causes the fluid inside the fluid inside the cochleacochlea to to move.move.

a. Cochlea is snail a. Cochlea is snail shaped structureshaped structure

IV. SOUNDIV. SOUND

2. The movement of fluid 2. The movement of fluid causes the hair cells lining causes the hair cells lining the cochlea to movethe cochlea to move

a. Damage to hair a. Damage to hair cells cells causes hearing losscauses hearing loss

IV. SOUNDIV. SOUND

3. Electrical impulses 3. Electrical impulses are sent along the are sent along the auditory auditory nervenerve to the brain. to the brain.

a. Sound is interpreted a. Sound is interpreted by by the cerebrumthe cerebrum

b. Auditory nerve b. Auditory nerve damage damage also causes hearing also causes hearing lossloss

IV. SOUNDIV. SOUNDP P inneainnea

EE ar canalar canal

T T ympanic membraneympanic membrane

MM alleusalleus

I I ncusncus

SS tapestapes

O O Val windowVal window

C C ochleaochlea

A A uditory nerveuditory nerve

V. BALANCEV. BALANCE

A. Spin DemoA. Spin Demo

B. The inner ear also sends B. The inner ear also sends messages to the brain messages to the brain about the position of the about the position of the head.head.

C. C. Semicircular CanalsSemicircular Canals- -

V. BALANCEV. BALANCE

C. C. Semicircular CanalsSemicircular Canals

1. Fluid filled1. Fluid filled

2. Lined with hair cells2. Lined with hair cells

3. Tilting the head causes 3. Tilting the head causes the fluid to move and the the fluid to move and the hair cells to bend.hair cells to bend.

V. BALANCEV. BALANCE

C. C. Semicircular Canals Semicircular Canals (cont)(cont)4. Nerve impulses are sent 4. Nerve impulses are sent to the brain to be interpretedto the brain to be interpreted

a. Cerebellum?a. Cerebellum?5. Motor neurons cause the 5. Motor neurons cause the neck muscles to adjust the neck muscles to adjust the position of the head. position of the head.

VI. TOUCHVI. TOUCH

A. Sensory neuron receptors A. Sensory neuron receptors are found in the skinare found in the skin1. Temperature Neurons1. Temperature Neurons

a. Cold- Found near a. Cold- Found near the the skin surfaceskin surface

b. Heat-Found b. Heat-Found deeper in deeper in the dermisthe dermis

VI. TOUCHVI. TOUCH

c. Indicates that cold c. Indicates that cold is is more of a threat than more of a threat than

heatheat

VI. TOUCHVI. TOUCH

2. Light Pressure Neurons2. Light Pressure Neurons

1. Found in fingertips, 1. Found in fingertips, eyelids, lips and the eyelids, lips and the

tip of tip of the tonguethe tongue

2. More sensitive 2. More sensitive areas areas of the bodyof the body

VI. TOUCHVI. TOUCH

3. Heavy Pressure Neurons3. Heavy Pressure Neurons

1. Found in joints, 1. Found in joints, muscle tissue and muscle tissue and certain certain organsorgans

2. Also found in 2. Also found in hands, hands, and feetand feet

VI. TOUCHVI. TOUCH

4. Pain Receptors4. Pain Receptors

1. Found in all body 1. Found in all body tissues except brain tissues except brain tissuetissue