Anatomy | Blogs
Sunday, January 29, 2012
Do Sea Urchins Have Eyes?
Have you ever see a sea urchin? The word sea urchin comes from the Old English word that means spiny hedgehog -- that is a pretty good description! It looks like a plant, but it's not one. It is an animal, specifically an invertibrate, that lives in salt water. An invertibrate is an animal without a backbone. If you look closely, you will see that it does not have any eyes. So how does it see? Image from University of Gothenburg Scientists have found that sea urchins have light-senstive receptor cells that act like retinas. These cells are found in sea urchins feet and among their 1,400 spines. Essentially, the sea urchin itself acts...
Friday, March 25, 2011
Lavender and Black Tile? Are You Color Blind?
My grandfather tiled a bathroom with lavender and black tile – it was truly hideous. My mother believed that my grandfather was color blind, so it looked fine to him. The lesson here is do not let a color blind person decorate your house! Why was my grandfather color blind? The back of your eyeball is called the retina and in the retina are two different types of cells that read light, rod cells and cone cells. There are three different types of cone cells that read the wavelengths of light: S cones read the short light wavelengths and are also called Blue cones M cones read the medium light wavelengths and are also...