The empty hemoglobin molecules then bind with the tissue's carbon dioxide or other waste gases, transporting them away. The average life cycle of a red blood cell is 120 days. As we have seen before, your bone marrow is continually producing new blood cells, replenishing your supply. Blood platelets , or thrombocytes, are not true cells, but rather cytoplasmic fragments of a large cell in the bone marrow, the Megakaryocyte . Platelet activation occurs when injury to the vessel wall exposes sub-endothelial components, especially collagen.
Platelets adhere to the damaged area and become cohesive to other platelets.
This aggregation leads to the formation of a platelet plug, which prevents further blood loss and allows the repair process to begin. This process is also know as clotting. Clotting must be carefully controlled because a clot in the wrong place, at the wrong time, can lead to stroke, heart attack, or death. White Blood Cells - White blood cells, also called leukocytes, are outnumbered by red blood cells by about six hundred to one. Lymphocytes originate in the bone marrow and become specialized as they are released into the blood stream.