What is the primary function of bone marrow?

The primary function of bone marrow is to produce blood cells, which encompasses erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). This process, known as hematopoiesis, occurs in the red bone marrow. The body requires a continuous supply of these cells to perform essential functions such as transporting oxygen, fighting infections, and aiding in clotting.

While other functions related to bones are critical, such as providing structural support, storing fat in yellow bone marrow, and housing protective elements for internal organs, these do not define the primary role of bone marrow. The unique tissue and cellular processes within the marrow are vital for maintaining healthy blood cell levels, making the production of blood cells the key function of bone marrow.