There are three types of blood cells: red blood cells (Erythrocytes), white blood cells (Leucocytes), and platelets. Blood cells are produced from stem cells in haemopoietin tissue. After birth this is primarily the red bone marrow, found in flat and irregular bones such as the sternum, hipbone, and vertebrae. Lymphocytes mature and divide in lymphatic tissue, found in the spleen, lymph nodes, and thymus gland. The thymus contains stem cells that produce T lymphocytes, and the stem cells in other lymphatic tissue also produce lymphocytes (Guyton, 1982).
Fig. 1-11 (i) Formation of Blood Cells
Fig. 1-11. RBC (A) and Hemoglobin (B).