Hematology and Its Practice

Hematology is the branch of medicine that deals with blood. This includes functions of blood, organs and organisms in the body that create blood, and diseases that are concerned with the blood. Each component of the blood has an equally important role and the body cannot function properly if one of these abilities is in some way hindered. Blood itself is composed of plasma, platelets, and red and white blood cells. Each of these parts work together inside the human body in order to make a fully-functioning human; if any of the components of the blood fail, the rest of the body will not be able to function properly.

Adult humans have approximately five liters of blood in their bodies at one time. The most abundant cells in human blood are red blood cells. These cells are proteins which create iron and function to allow oxygen to travel throughout the body (Franklin 2011). Although most people believe that blood is always red, that is actually only the color once the blood has been oxygenated outside the body. Internally, blood is blue or purplish in color. Like skin cells and other body parts which degenerate, die, and then grow anew, red blood cells can die and the body produces new ones. The average life span of each red blood cell is approximately four months. Plasma, another component of human blood, is primarily water and it functions to allow the other blood cells and particles to move about the body fluidly. It is yellowish in color in its natural state. The white cells are responsible for fighting disease in the body. Human immune systems are dominated by these cells. They help the body fight off infections and various viral and bacterial enemies. White cells have a considerably shorter life span than red cells. The white cells usually only live a few days up to a week. Platelets serve to allow the blood to coagulate when an injury has been done to the body. Were it not for this process, colloquially referred to as scabbing over, humans would potentially bleed to death from even the smallest scratch.

Dr. Lawrence Bass (2010) stated in an article for Blood Magazine that Platelets clot wounds because of calcium, vitamin K, and the protein fibrinogen. When it reaches fresh oxygen, the fibrinogen has a chemical reaction which produces fibrin. The fibrins form miniscule threads which allow the blood to harden creating a scab. "Prior to vascular injury, platelet activation is suppressed by endothelial cell-derived inhibitory factors" (page 388). Therefore, the platelets are not always creating fibrin. They function within the blood stream but travel through the blood stream at a brisk rate to meet the site of injury as expeditiously as possible.

If an injury to the body is too great for the self to regenerate and clot in a timely enough manner to benefit the person, a blood transfusion can be performed by doctors. This requires blood from another human being, one who has the same blood type as the injured individual. Blood types can be A, B, AB, or O. with A and B type blood being genetically dominant to O. Since it is a recessive blood type and therefore neutral, O-type blood can be used in all patients, even if they are not the same. O is called the "universal donor" because even someone with AB blood can receive O. blood successfully. There are also Rh factors which determine if a blood type is positive or negative. What this means is that a specific blood protein is looked for in human blood strains. Whether a person does or does not possess this protein will determine if the blood type is positive or negative.

Blood is pumped throughout the body through the cardiovascular system, controlled by the heart. The left ventricle pumps the blood into the rest of the body from the heart and it circulates through the body to return to the heart on the right side of the organ. Besides carrying oxygen, plasma also ensures that hormones are circulated and waste products are removed from the body.

Doctors specializing in hematology are logically called hematologists. Blood diseases are any that can affect production of blood or any of the components of blood such as the cells, hemoglobin, blood proteins, and the function of coagulation. According to the American Society of Hematology (2010), hematologists are beginning to prove that other cancers and ailments can begin with the blood stream. Therefore, one of the first tests doctors usually perform on ailing patients is a CBC or complete blood count. This information is used as a building block to investigate. Like any part of the body, chemical, viral, bacterial, or genetic influences can cause complications in the blood which create health problems. Platelets are an extremely important component of the blood stream and the body's regenerative abilities. However, there can be dangers associated with the clots. For example, a blood clot that forms internally can block the flow of blood which will, in turn, cut off the flow of oxygen to the part of the body where the clot is located. This can lead to paralysis in that limb or even death if the clot affects the arteries of the brain.