The Interpretation of Qualitative Changes in Neutrophilic Leukocytes
The neutrophilic granulocyte (polymorphonuclear neutrophilic leukocyte) plays a major role in the mechanism of defense against infection and toxemia. The defensive value of this cell depends upon its maturity and the integrity of its chemical substances which normally enable it to dispose of bacteria and poisons. The quality of the neutrophilic granulocyte is thus even more important than the quantity.
The granulocyte is essentially a drop of protoplasm containing active ferments surrounded by a membrane. Anything interfering with the development of the protective substances or injuring them must impair the usefulness of the cell. All granulocytes are formed in the bone marrow. Each cell goes through a definite cycle of development and maturation before entering the circulation. When a granulocyte is released from the marrow, its development normally is complete. No further changes take place while it is in the circulation or tissues except those incidental to the death of the cell.
The granulocytes have no function in the blood stream. All cells in the circulation are only passing from the site of formation in the marrow to the point of excretion or localization in the tissues. The mature granulocyte circulates only a short time, certainly not more than three or four days. When a cell dies in the circulation or leaves the blood stream to be excreted by a mucous membrane or to localize in the tissues, another emerges from the marrow to keep the total number at a relatively fixed level. Five to ten billion neutrophilic granulocytes are. . .