Plasma (noun, “PLAZ-muh”)
The word plasma can mean two very different things. In physics, plasma
refers to one of the four states of matter, along with solid, liquid and gas.
Plasma is gas that has an electric charge.
Plasmas form when extra energy — such as heat — is added to a gas. This
extra energy can knock electrons off the atoms or molecules in the
gas. What’s left is a mix of negatively charged electrons and positive ions. That mix is plasma.
Because plasmas are made of charged particles, they can do things that
ordinary gases cannot. For instance, plasma can conduct electricity. Plasmas
also can respond to magnetic fields. Plasma might sound exotic, but it’s the
most common state of matter in the universe. Stars and lightning bolts
contain plasma. Human-made plasmas glow in fluorescent lamps and neon signs.
In medicine, the word plasma refers to the liquid part of blood. This yellowish fluid makes
up about 55 percent of our blood. The rest is red blood cells, white blood
cells and platelets. Plasma is about 90 percent water and seven percent
proteins. The fluid also contains vitamins, hormones and
other ingredients.
Blood plasma has a lot of important jobs. It delivers nutrients to cells
and carries away cellular waste. Plasma also shuttles proteins for blood
clotting to injuries, helping the body heal. And it carries antibodies that
help fight off infection. Donated blood plasma can be used to treat burns and
other injuries. It’s also used to treat patients with immune diseases, bleeding
disorders and other chronic illnesses.
Комментариев нет:
Отправить комментарий