Showing posts with label Blood Vessels. Show all posts
Showing posts with label Blood Vessels. Show all posts

Saturday, April 6, 2013

What is an albino?


True albinos, like the white, pink-eyed rabbit pets, are born without any coloring matter in their bodies. An albino is a person born without any coloring matter or pigment, in his skin.  In such a person the skin is milky-white and the hair is very light.

A person who is a true albino also has pink eyes because the iris (the colored part of the eye) is so clear that the tiny blood vessels of the eye shines through.  In normal eyes, the color of the iris serves to hide the pinkness.

The color of our skin is chiefly due to the presence of a color pigment called “melanin,”  which gives the skin what we call “flesh color.”

When melanin accumulates in small spots in the skin, freckles appear.  And when you spend a few days in the sun, the sunlight darkens the melanin in your skin and this results in a “suntan.”

Albinism is found not only in man, but among all kinds of animals and birds, and it is even found in plants.  Perhaps the animal albinos we are all most familiar white mice and rats and rabbits that have pink eyes.

White ducks, chickens and horses are not true albinos, because most of them have color pigments in eyes, beaks or legs.-Dick Rogers

Thursday, April 4, 2013

How do fish breathe in the water?


As the fish forces water past its gills tiny blood vessels lining the gills  absorb oxygen out of the air that is dissolved in the water.

Just as  our lungs take oxygen from the air.  Fishes take oxygen from the water.  But fishes breathe with gills instead of lungs. By watching a fish in an aquarium,  You can see it open and close  its mouth constantly as though drinking in gulps of water.

Each time the fish opens its mouth a mouthful of water is drawn in. Then the fish closes its mouth and the water is forced back out through the gill openings, which  are the slits located on the side of the fish’s head. The gills are very  thin tissues.  They are bright red because they contain many tiny blood vessels.

As the water passes over  the gills the oxygen dissolved in the water is absorbed  into  the tiny blood vessels and is carried by the blood to other parts of the fish’s body. (Fishes have nostrils which they use only for smelling.)

Fish live wherever there is water, except in  very salty  water, such as the dead sea and  the great salt lake of Utah, or in water polluted by man. In such water fish cannot find enough oxygen to breathe. – Dick Rogers