All blood cells are mostly of three types - RBC (red blood corpuscles), WBC â€" (white blood corpuscles) and platelets. Red blood cells are found in abundance in a vertebrate. Red blood cells are formed in the flat bones of our body. The interior of the bones contains a flexible tissue called bone marrow, a key element of the lymphatic system. It is a spongy and fatty tissue that houses stem cells, which are biological cells that can divide by the process of mitosis and self renews to form more of its own kind. The bone marrow is mainly of two types - red bone marrow and yellow bone marrow. RBC, WBC and platelets are all formed in the red bone marrow, which contains blood vessels and capillaries in large volume. The major function of a stem cell, which transforms themselves into RBC, WBC and platelets, is to maintain circulation in the body. They even help in protection and immunity. Stem cell has the nature of regeneration. Thereby, when the cells get weakened and damaged they need repair, and these stem cells transform into RBC, WBC and platelets and in this way, the older damaged cells get replaced, and new blood cells are formed.
Bone marrow in an adult, bone marrow and spleen in an infant, spleen and liver in a fetus.
The heart is the part of the body pumps blood...