Bone Marrow

blood · inside-your-bones · cell-factory · human-body

Blood cell factory. Bone marrow is where your body makes brand new red blood cells, white blood cells, and platelets every single day. Without bone marrow, your blood couldn't do its job of carrying oxygen and fighting germs.

Hidden in spongy bone. Bone marrow lives in the squishy, porous parts of certain bones like your ribs, spine, breastbone, and hip bones. It's tucked away safely inside where it's protected.

Weighs as much as a pet. In an average adult, bone marrow makes up about 5% of your total body weight. If you weigh 100 pounds, about 5 pounds of that is bone marrow.

Made of special cells. Bone marrow contains hematopoietic cells that create blood, fat cells that store energy, and helper cells that support everything. It's like a mini city with different neighborhoods doing different jobs.