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.