RT Book, Section A1 Blackwood, Alexander A1 Boxer, Lawrence A. A2 Rudolph, Colin D. A2 Rudolph, Abraham M. A2 Lister, George E. A2 First, Lewis R. A2 Gershon, Anne A. SR Print(0) ID 7040947 T1 Chapter 441. Disorders of Granulocytes T2 Rudolph's Pediatrics, 22e YR 2011 FD 2011 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-149723-7 LK accesspediatrics.mhmedical.com/content.aspx?aid=7040947 RD 2024/04/19 AB White blood cells, or leukocytes, are part of the innate immune system. They are one of the body’s major defenses in preventing and combating infection. The most common types of leukocytes are lymphocytes, monocytes, and granulocytes. This chapter will deal primarily with granulocytes. These cells are derived from stem cells in the bone marrow and have diverse functions. The most common of the leucocytes is the neutrophil. Deficiency of neutrophils, called neutropenia, is one of the most common hematologic abnormalities during childhood and when severe can result in life-threatening infection.