The Function of Blood

If we take a sample of blood then the sample is treated with an agent to prevent from clotting, and then spin that sample using a centrifuge, the blood sample will separate into two parts:

• The red cell will settle in the bottom
• The white cells settle on top of them forming the “buffy coat”.

Those fraction of red blood cells is called as hematocrit, generally it approximate of 45%, if the value is much lower than this, you must be careful because this is once of a sign having Anemia.

 

As a general, blood has two major functions:
1. Transport through the body of:

• Oxygen and carbon dioxide
• Food molecule (glucose, lipids, amino acids)
• Ions (e.g. Na+, Ca2+, HCO3-)
• Waste (e.g. urea)
• Hormones
• Heat

2. Defense of the body against infection and other foreign materials, all the WBCs participate in this defense.

 

Blood produce with two different kinds, first produce in the bone marrow, second are from a single type of cell called a hematopoietic stem cell. Actually blood producing by stem cell is very rare only about one of 10,000 bone marrow cell.

 

Producing blood cell by stem cell also can attached (probably by adherents junctions) to osteoblasts lining the inner surface of bone cavities, and also express a cell-surface protein designed CD34. Stem cell can produce by mitosis, two kind of progeny.

Emotion Effect to Blood Pressure

How does the intricate relationship between emotions and bodily changes work? The answer lies in the way the brain and nervous system are set up. The Human brain in somewhat like the central processing unit of a computer; It recives and processes information and controls body movements.

Another part of the nervous system, the autonomic nervous system (ANS), is like a video display ternimal on which the emotional message from the computer is printed out. We read the message in the form of increased secretion of sweat glands, tightening of the stomach muscles, or other physical reactions. When you stand in front of a classroom to give a report and your eyes survey the sea of faces waiting for your brain, which interprets what the eyes see and sends out its own message panic. The ANS then "print out" that message, and your hands turn clammy while your stomach churns.

Blood Pressure Effect.
This term refers to the force exerted by the heart to push blood out of the arteries. A healthy adult blood pressure might be 120/80, for example. This would mean that when the heart contracts to push mercury up to 120 mm (millimeters) in a measuring device (known as a sphygmomanometer). When the heart relaxes after the contraction, the pressure pushes the mercury up only 80 mm. There are great changes in blood pressure during highly charged emotional states.