What is blood?
What is blood? Blood is a red viscous substance that circulates inside the human body and animals. It is composed of billions of cells that help in various ways.
The blood is composed of substances and different micro-organisms called cells which are essential for our survival. These main cells include red blood cells, white blood cells, and platelets. It is also composed of a yellow substance called plasma. Red blood cells are disc shaped containing hemoglobin which allows the ability to pick up oxygen and other nutrients and transport them to all areas of the body and also pick up waste products which are delivered to the lungs where they get disposed. Red blood cells are made in the bone marrow.(1)
Red Blood Cells
White blood cells are the soldiers because they fight infections. When a foreign micro organism enters the body, the white blood cells arrive and attack the organism to prevent the spread of infection. Sometimes battles are lost and the person gets sick.(1)
White Blood Cells
Platelets help with the clotting mechanism of the blood.The blood is composed of a yellow substance called plasma which is composed of 95% water and 5% of diluted proteins, salts, and other nutrients. It’s function is to carry cells, nutrients, enzymes, and hormones.(2)There is no substitute for blood because it cannot be made. When people lose blood, the only way to replace it is by transfusing blood that has been donated by other people. There are 5 million red blood cells, 8,000 white blood cells, and 250,000 platelets in one drop of blood.(2)
1. America’s Blood Center, “What is blood.” Available at http://www.americasblood.org/go.cfm?do=page.view&pid=11. Accessed December 15, 2008 2. Librarythinkquest.com, “what is blood?” Available at http://library.thinkquest.org/5777/cir4.htm. Accessed December 15, 2008
Return from what is blood to the heart
Return to the home page
|
