CK12 Life Science

Seeing in Three Dimensions Did you ever use 3-D glasses to watch a movie, like the boy inFigure20.12? If you did, then you know ...

Figure 20.13: Humans with color vision see the apples on this tree; the bright red color of the apples stands out clearly from t ...

Evolution and Primate Vision Why do you think primates, which include humans, evolved the ability to see in three dimensions and ...

You can also watch an animation of the eye at http://pennhealth.com/health_info/ animationplayer/seeing.html. Figure 20.16: The ...

Figure 20.17: Light from objects at different distances is focused by the lens of the eye; muscles in the eye control the shape ...

Colors of Light Visible light from the sun is colorless. However, if you bend visible light by passing it through a prism, it pr ...

Figure 20.20: These plastic beads reflect light of different wavelengths, so they appear to be different colors. ( 3 ) vision pr ...

In myopia, the eye is too long. As shown inFigure20.22, this results in images being focused in front of the retina. Myopia is c ...

Further Reading / Supplemental Links CK12 High School Biology, Chapter 35http://www.fda.gov/CDRH/LASIK Body Atlas.Nerves, Brain ...

retina Layer of light-sensing cells that covers the back of the eye. visible light Electromagnetic radiation that humans can det ...

Figure 20.23: This outdoor fruit market stimulates all the senses—sight, sound, smell, taste, and touch. ( 25 ) Hearing and Bala ...

explain how your ears sense the sound. Each numbered step refers to a structure with the same number inFigure20.25andTable(20.2) ...

the ear. At the end of the ear canal, the sound waves strike the eardrum. This is a thin membrane that vibrates like the head o ...

Figure 20.26: This gymnast is using the semicircular canals in her ears, along with the cerebellum in her brain, to help keep he ...

Touch When you look at the prickly cactus inFigure20.28, does the wordouchcome to mind? Touching the cactus would no doubt be pa ...

temperature of the water in a lake before jumping in. You might stick one bare foot in the water. Neurons in the skin on your fo ...

Figure 20.29: Reflex Arc: When you touch something hot, you may jerk your hand away without even thinking about it; the nerve im ...

Figure 20.30: Reflex Arc: When you touch something hot, you may jerk your hand away without even thinking about it; the nerve im ...

Figure 20.32: Tiny bumps that cover the tongue contain taste buds, bundles of sensory neurons that allow you to detect different ...

taste and smell allow us to enjoy the flavor and aroma of our favorite foods. These five senses not only enrich our life. They a ...