1. Our Senses Chapter 8.2

2. It is TRUE that when you look at a rainbow, the wavelength of light determines the colors you see –Red wavelength is longer than orange & continues to get shorter until violet which has the shortest wavelength

3. Light Electromagnetic energy –Described in wavelengths –Not all light is visible to humans –Wavelengths can be a fraction of an inch to miles long (cosmic- radio)

4. The Eye Similar to a camera Amt. of light that enters is determined by opening of the colored part of eye –Blk. area is pupil –Pupil size is sensitive to our emotions Light then encounters the lens; adjusts to the distance of objects by changing its thickness –Squinting is people adjusting their lenses

5. The changed image is projected onto the retina –Like the film in camera; neurons that are sensitive to light (photoreceptors) carries the input to the brain –Information is relayed to visual area of brain Blind Spot –We all have one, area of eye where there are no photoreceptors

6. Rods & Cones –Rods-sensitive to brightness –Cones-provide color vision Adaptation –May take time for eyes to adjust to a dark room –Adaptation to bright light happens more quickly Visual Acuity –Sharpness of vision –Ability to see visual details

7. Color Vision People with normal color vision see any color in the spectrum of visible light When one color stimulates the cones, we perceive more colors Color Blindness; people who do not have normal color vision –Malfunction of cones

11. Hearing Hearing depends on the vibrations of the air (known as sound waves) –Once the sound waves hit the ear, tiny hair cells move back & forth –Hair cells then change sound vibrations into neuronal signals that go to the brain Loudness=amplitude (or height) of sound –Measured in decibels Normal range of hearing is from 0-140 decibels –Damage can be done to your ear @ 110 decibels Look on website info. http://www.centerpointaudio.com/ Earbud-Safety.aspx

12. How we hear sound Watch the short video about how we hear:

13. Deafness 2 Types –Conduction; when there is a hindrance of physical motion through the outer/middle ear OR damage to the bones –Hearing aid can help Sensor neural –Damage to the cochlea, the hair cells or auditory neurons –Need a cochlear implant to help

14. Balance Sense of balance is regulated by the inner ear Overstimulation can cause dizziness & motion sickness

15. Smell & Taste Check back here! We’ll be doing an experiment over smell & taste on Tuesday