Tuesday, December 1, 2009

all about BLOOD.

Blood Donation


              Blood plays a vital role in saving human life, and because scientists have yet to succeed in discovering a suitable replacement for blood, blood donation remains the most important means for transferring blood from one human to another.
              Blood donation refers to the giving of extra blood that is unnecessary for the body to someone in need. Giving blood is by no means dangerous because the human body normally contains 17-18 glasses of blood, of which only 15-16 is actually used. The extra portion can be donated to others.
              Blood donation can be done as often as every 3 months. This is because when some blood has been donated, the bone marrow plays an important role in producing new blood cells to replace blood loss to maintain the same blood volume. If one does not donate blood, the body will routinely excrete the degenerated blood cells in the form of urine, feces, or sweat. The process of blood donation usually takes approximately 15 minutes. 350-450 c.c. of blood, depending on the donor's weight, will be stored in a blood bag.

What is Blood?
                 Blood is the red fluid which, with the help of the heart, circulates in blood vessels throughout the body. Blood cells are created by bone marrow located in the arms, chest, ribs, skull, hips, spine, etc. An adult body normally contains 4,000-5,000 c.c. of blood. This can be easily calculated through the formula:
total body weight x 80 = blood volume (c.c.)

Blood consists of 2 components, namely:
         1. Blood cells, which make up 45% of whole blood. They are of 3 types:
                 1.1 Red blood cells. Replaced every 120 days, they transfer oxygen to the cells to create energy.
                 1.2 White blood cells. Comparable to soldiers, they prevent and destroy "intruders" to the body such as bacteria, virus, and other toxic substances. They live approximately 10 hours.
                 1.3 Platelets. Having a life span of 5-10 days, they make blood clot.
         2. Plasma 55% of whole blood, plasma is a yellow liquid that keeps blood cells afloat. In addition to maintaining blood pressure and volume, it also serves as immunity. It consists of 92% liquid and 8% proteins. The essential proteins are:
                 - Albumin, which preserves the balance of water in blood vessels and tissues.
                 - Immunoglobulin, which makes the human body immune to certain diseases.
           Interesting facts:
                 - The accumulated length of all blood vessels in the body is 96,000 kilometers or 2.5 times greater than the earth's circumference.
                 - On average, a male body contains 5-6 liters of blood while there are 4-5 liters in a female body.
                 - Blood circulates back to the heart as many as 1,000 times a day.
                 - Young people's bodies contain 35,000,000,000,000 (35 trillion) red blood cells. After 120 days, 1.2 billion red blood cells will expire and be excreted while the bone marrow, much of which is located in the ribs, skull and spine, will create new cells to replace the degenerated ones.

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