This is a rare peek at how cartilage transforms into bone. In this image, you can see cartilage (in purple and white), blood vessels and cells (in yellow), and other specialized cells that create ...

Medically reviewed by Gagandeep Brar, MD Key Takeaways Bone marrow fills the cavities in your bones and produces blood cells.Red blood cells carry oxygen, white blood cells fight germs, and platelets ...