Blood Basics

The Bombay blood group is a rare exception to the commonly accepted ABO blood types. It is observed to occur in 1 out of every 250,000 people except in parts of India where the incidence has been observed to be as much as 1 in 7600. The rare designation was first identified in Mumbai, also known as Bombay - thus the name of the blood group. The blood type is thought to occur in only those of (Eastern) Indian descent. Blood types are actually ways of differentiating the type of antigens on a person's red blood cells.

Haemoglobin is the iron-containing protein attached to red blood cells that transports oxygen from the lungs to the rest of the body. Haemoglobin bonds with oxygen in the lungs, exchanges it for carbon dioxide at cellular level, and then transports the carbon dioxide back to the lungs to be exhaled.Whether haemoglobin binds with oxygen or carbon dioxide depends on the relative concentration of each around the red blood cell.

The human immune system has various ways of responding to an infection caused by bacteria or viruses. Our bodies produce proteins (antibodies) that are highly specific for the infectious agent as a part of our "humoral" immune response. The antibodies help stop the infection from spreading further and help to eliminate the bacteria or virus from the body.Antibodies are also used to help our bodies find and destroy "foreign" cells such as tumors.

The blood moves through the body through the blood vessels -- essentially, flexible tubes that branch out and subdivide. There are different types of blood vessels: the arteries, capillaries, and veins.

Plasma is the transporting medium for a myriad of hormones, electrolytes, sugars, waste products, and other substances. It is especially useful in transfusion medicine, as it provides the starting material for the preparation of critical blood-clotting factors, albumin and immune protein preparations. The clotting factor concentrates, prepared from large batches of pooled plasma, provide life-saving treatment for blood clotting disorders such as hemophilia.

The blood cells called platelets (thrombocytes) help blood to clot, in several different ways. When bleeding occurs, platelets clump together to help form a clot. Also, when they are exposed to air (as they would be by a wound), platelets start breaking down and release a substance into the bloodstream. This substance starts a chain of chemical events that eventually causes a protein in the blood, fibrinogen, to turn into a different substance, fibrin, which forms long threads. These threads tangle up red blood cells to help form a clot, or scab, over the wound.

White Blood Cells are responsible for protecting the body from invasion by foreign substances such as bacteria, fungi, and viruses. The majority of white blood cells are produced in the bone marrow, where they outnumber red blood cells by two to one. However, in the blood stream, there are about 600 red blood cells for every white blood cell. There are three types of white blood cell: granulocytes, lymphocytes, and monocytes. There are, in turn, three kinds of granulocyte: neutrophils, eosinophils, and basophils.

Red Blood Cells are perhaps the most recognizable component of whole blood. Red blood cells contain hemoglobin, a complex iron-containing protein that carries oxygen throughout the body and gives blood its red color. The percentage of blood volume composed of red blood cells is called the “hematocrit.” The average hematocrit in an adult male is 47 percent; the average hematocrit in adult females is 42 percent. There are about one billion red blood cells in two to three drops of blood, and, for every 600 red blood cells, there are about 40 platelets and one white cell.

Whole Blood is a living tissue that circulates through the heart, arteries, veins, and capillaries carrying nourishment, electrolytes, hormones, vitamins, antibodies, heat, and oxygen to the body's tissues.

Blood cells are produced in the bone marrow, a jellylike substance inside the bones that is composed of, among other things, fat, blood, and special cells that turn into the various kinds of blood cells. In children, the marrow of most of the bones produces blood. But in adults, only the marrow of certain bones -- the spine, ribs, pelvis, and some others -- continues to make blood. Bone marrow that actively produces blood cells is called red marrow, and bone marrow that no longer produces blood cells is called yellow marrow.