where do you find red marrow

Red marrow is found inside certain bones, mainly in the central part of the skeleton and the ends of some long bones in adults.

What red marrow is

• Red marrow is the blood‑forming type of bone marrow (it makes red blood cells, white blood cells, and platelets).

• It sits in the spongy (cancellous) part inside bones rather than on the bone surface.

Where you find red marrow in adults

In a typical healthy adult, red marrow is mainly in:

• Axial skeleton (central bones):
  • Skull and other cranial bones.

* Vertebrae (spine).

* Ribs and sternum (breastbone).

* Pelvis/hip bones.

• Proximal ends of long bones:
  • Upper ends of the femur (thigh bone).

* Upper ends of the humerus (upper arm bone).

How this changes with age

• In infants and young children, red marrow is present in most bones , including the shafts of long bones.

• After about age 5, much of that red marrow is gradually replaced by yellow (fatty) marrow, so in adults it mainly remains in axial bones and the proximal ends of the femur and humerus.

Quick contrast with yellow marrow

• Red marrow: active in blood cell production (hematopoiesis).

• Yellow marrow: mainly fat storage and can convert back toward red marrow if the body needs more blood cell production (for example after major blood loss).

Information gathered from public forums or data available on the internet and portrayed here.