Hematology is the name of the area of medicine that focuses on the blood, diseases affecting the blood, and closely related organs and tissues, such as bone marrow and the spleen. An atlas of hematology is a medical reference work that contains detailed photographs of different types of blood cells. It shows both the appearance of cells in their healthy state and how they look when affected by various disorders and illnesses. Its purpose is to help doctors and other medical personnel analyze blood cells and identify the cause of blood-related health problems. An atlas of hematology is usually a physical book, though today it can also take the form of an archive stored on a computer or an optical disc, such as a DVD.
An atlas of hematology covers several different types of cells, such as red blood cells, various types of white blood cells such as neutrophils and lymphocytes, and platelets. It includes both images of these cells as they normally appear and how they appear when affected by pathogens in the bloodstream or by disorders that interfere with their normal production and development, such as sickle cell anemia and thalassemia. Atlases also contain images of other cells closely tied to the bloodstream, such as bone marrow and lymph node cells. Foreign microorganisms that infect the blood may also be shown.
Another type of cells covered in an atlas of hematology are cancerous cells, such as the malignant cells that cause lymphoma and leukemia. Closely related are abnormal blood cells that are not themselves cancerous but often appear in the presence of cancers affecting the blood, such as the damaged white blood cells that appear in large numbers in people suffering from leukemia. This information is important in the diagnosis of these diseases.
In addition to general references, atlases of hematology with a more specific emphasis also exist. For instance, some atlases are focused on identifying different types of cancerous cells. Atlases intended for veterinary medicine or animal research display blood cells of various animal species rather than humans and can be general works covering large numbers of common animals or specialized texts focused on specific types of animals, such as rodents or avians. In some cases, an atlas of hematology may include additional explanatory text introducing important concepts and terms in hematology so that the atlas can be used as an instructional text for medical students.