Blood ... Part 1

It is said that, 7 - 8% of the human body weight is from blood.

The Blood Functions :
<-> transport oxygen & nutrients to our cells
<-> get rid of carbon dioxide & other waste products
<-> maintaining constant body temperature


The Blood Components :
<-> red cells
<-> white cells
<-> platelets
<-> plasma


Red Cells [erythrocytes] :

• Make up of 40-50% of total blood volume.
• They transport oxygen from the lungs to all of the living tissues of the body and carry away carbon dioxide.
• The red cells are produced continuously in our bone marrow from stem cells.
• The red cells remain viable for only about 120 days before they are removed from the blood and their components recycled in the spleen

White Cells [leukocytes] :

• Make up of about 1% of blood volume.
• Mostly produced in our bone marrow from the same kind of stem cells that produce red cells.
• Some white cells are a major part of the immune system, protect our bodies from infection by surrounding and destroying bacteria, viruses, fungi, or other parasites.
• They also have the function of getting rid of old, unneeded blood cells as well as foreign matter such as dust and asbestos.
• Individual white cells usually only last 18-36 hours before they also are removed.

Platelets [thrombocytes] :

• These are cells that clot blood at the site of wounds by adhering to the walls of blood vessels, thereby plugging the rupture in the vascular wall.
• Can release coagulating chemicals which cause clots to form in the blood that can plug up narrowed blood vessels.
• Research has shown platelets help fight infections by releasing proteins that kill invading bacteria and some other microorganisms.
• Platelets also stimulate the immune system.
• Have a lifespan of 9-10 days.
• Produced in bone marrow from stem cells.

Plasma :

• A clear liquid protein and salt solution.
• Carries the red cells, white cells, and platelets.
• Normally, 55% of our blood's volume is made up of plasma. About 95% of it consists of water.
• As the heart pumps blood to cells throughout the body, plasma brings nourishment to them and removes the waste products of metabolism.
• Plasma also contains blood clotting factors, sugars, lipids, vitamins, minerals, hormones, enzymes, antibodies, and other proteins.