The blood cells that are made inside certain bones in your body are red blood cells, white blood cells, and platelets. This process is called hematopoiesis and occurs primarily within the bone marrow, which is the soft, spongy tissue found inside certain bones.

Here's a breakdown of the different types of blood cells and their functions:

* Red blood cells (erythrocytes) carry oxygen from the lungs to the rest of the body.

* White blood cells (leukocytes) are part of the immune system and help fight infections.

* Platelets (thrombocytes) help stop bleeding by forming blood clots.

The bones that contain the most active bone marrow include:

* Flat bones: like the ribs, sternum (breastbone), and skull bones

* Long bones: like the femur (thighbone), humerus (upper arm bone), and tibia (shinbone)

While most blood cell production happens in the bone marrow, some white blood cells also mature in other tissues like the lymph nodes and spleen.