How are platelets primarily formed in the body?

Platelets, also known as thrombocytes, are primarily formed in the body from bone marrow stem cells, specifically megakaryocytes. This process is known as thrombopoiesis. Megakaryocytes are large cells that mature in the bone marrow and, when they undergo a process called fragmentation, they release small cell fragments into the bloodstream that become platelets. Each megakaryocyte can produce thousands of platelets, which are essential for blood clotting and wound healing.

Understanding this process highlights the critical role of the bone marrow in hematopoiesis, where all blood cells, including platelets, are produced. This makes the bone marrow the correct source of platelet formation, distinct from other options that do not contribute directly to this process.