Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.

The cells found in the body fluid circulating throughout the CARDIOVASCULAR SYSTEM.

Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.

Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.

Abnormal intracellular inclusions, composed of denatured hemoglobin, found on the membrane of red blood cells. They are seen in thalassemias, enzymopathies, hemoglobinopathies, and after splenectomy.

Small, abnormal spherical red blood cells with more than the normal amount of hemoglobin.

Erythrocytes with protoplasmic projections giving the cell a thorny appearance.

Immature ERYTHROCYTES. In humans, these are ERYTHROID CELLS that have just undergone extrusion of their CELL NUCLEUS. They still contain some organelles that gradually decrease in number as the cells mature. RIBOSOMES are last to disappear. Certain staining techniques cause components of the ribosomes to precipitate into characteristic "reticulum" (not the same as the ENDOPLASMIC RETICULUM), hence the name reticulocytes.

White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).

Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.

Leukocytes with abundant granules in the cytoplasm. They are divided into three groups according to the staining properties of the granules

Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.

Granular leukocytes characterized by a relatively pale-staining, lobate nucleus and cytoplasm containing coarse dark-staining granules of variable size and stainable by basic dyes.