Blood

From the Simple English Wikipedia, the free encyclopedia that anyone can change

Blood is a liquid found in humans and most animals. Blood is pushed through the organism by the heart. Blood brings nutrients and oxygen to our tissues. Blood also takes away waste and carbon dioxide from tissues.

Blood is made up of blood plasma and various cells — red blood cells, white blood cells and platelets.

Contents 1 Plasma 2 Red blood cells 3 White blood cells 4 Platelets 5 Where does blood come from?

[change] Plasma

Blood plasma is the yellow liquid where the blood cells float. Plasma is made up of:

• nutrients
• electrolytes (salts)
• gases like nitrogen, and a small amount of oxygen and carbon dioxide
• proteins, like:
  • albumin
  • antibodies (also called immunoglobulins)
  • clotting factors
  • protein hormones
• waste
• lipids
• non-protein hormones

Plasma that does not contain the protein fibrinogen is called serum.

In a adult you have about 6 liters of Plasma. A baby has 1-2 liters. Plasma is a liquid, mostly water (90%) in blood plasma takes up 60%. Plasma is part of blood types.

[change] Red blood cells

Red blood cells carry oxygen and carbon dioxide around our body. Cells in our body need oxygen to live. Cells also make carbon dioxide as a waste. Red blood cells bring more oxygen around the body. They also take away the carbon dioxide.

Another name for red blood cell is erythrocyte. Erythro means red. -Cyte means cell. RBC is an acronym for red blood cell.

RBCs are filled with hemoglobin. This is a protein. It is made to carry a large amount of oxygen. Hemoglobin has iron in it. The iron and oxygen gives hemoglobin its red color. This is why blood is red. Erythropoietin promotes the creation of red blood cells.

RBCs also help the blood stay normal pH. The blood needs a to be at a pH of 7.4. If it is much more or less than 7.4 a person can get very sick or die. RBCs are a buffer for the blood pH. Buffer means that it stops changes in pH. The proteins and the carbon dioxide in the RBC are buffers for the blood.

[change] White blood cells

White blood cells are a big part of the immune system. White blood cells kill things that do not belong in the body. They kill germs such as bacteria and viruses. They kill cancer cells. White blood cells also and help fight other toxic substances.

Another name for white blood cell is leukocyte. Leuko means white. -Cyte means cell. WBC is an acronym for white blood cell.

WBCs do their job different ways. Some WBCs kill and eat germs and cancer cells. Some WBCs make antibodies. These are proteins that stick to a cell and tell other WBCs to kill it. Some WBCs make chemicals. They release these chemical to fight things that do not belong in the body. These chemicals cause inflammation in a part of the body. When a germ makes someone sick, the body shows it. If a bacteria gets under someone's skin and causes an infection, the skin gets red, hot, and painful. This redness, heat, and pain are signs of inflammation. This shows that WBCs are fighting the infection and killing the bacteria.

WBCs live in the blood. But they also go out of the blood too. WBCs are in lymph nodes. They also go out of the blood in places where there is infection. WBCs do this to fight the germs that make the infection.

There are different kinds of WBCs:

• lymphocytes
• neutrophils
• eosinophils
• macrophages
• mast cells

[change] Platelets

Platelets help make blood clot. A clot is when the liquid blood becomes solid. The body makes blood clot when the skin is cut. This stops blood from going out of the skin too much.

Platelets can also cause problems. Blood clots are good sometimes. But some blood clots are bad. If a blood clot happens in a blood vessel going to the brain, it can cause a stroke. If it happens in a blood vessel going to the heart, it can cause a heart attack.

Platelets are not the only things that make clots. There are proteins in the blood that help make clots. Both platelets and clotting proteins are needed to make good clots.

[change] Where does blood come from?

Blood cells are made in the bone marrow. This is the liquid in the middle of bones. Special cells in the bone marrow make all of the blood cells in your body.

Plasma proteins are made mostly by the liver. The water and electrolytes in plasma come from the food and water that you eat.