Red Bone Marrow: The Body's Blood Factory

 Red Bone Marrow: The Body's Blood Factory

Introduction 

*Visual: cross-section of a long bone.*

Narration: "Inside your bones is soft, spongy tissue called bone marrow. Red bone marrow is the part that makes your blood cells."

*Visual: close-up of red, spongy tissue.*

Narration: "Red bone marrow, also called myeloid tissue, is a highly vascular tissue found in the spaces of spongy (cancellous) bone. Its red colour comes from the large number of blood vessels and developing red blood cells."

**Scene 3: Function, hematopoiesis (25 sec)**

*Visual: a stem cell splitting into RBCs, WBCs and platelets.*

Narration: "Red marrow contains hematopoietic stem cells. These develop into red blood cells, which carry oxygen, white blood cells, which fight infection, and platelets, which help blood clot. This process is called hematopoiesis. An adult body makes millions of new red blood cells every second.

*Visual: skeleton with highlighted areas.*

Narration: "In children, red marrow is present in almost all bones. In adults, it is mainly in flat and irregular bones: the sternum, ribs, vertebrae, skull and pelvis, and at the upper ends of the femur and humer

*Visual: side-by-side comparison.*

Narration: "With age, much red marrow is replaced by yellow marrow, which mostly stores fat. In severe blood loss, yellow marrow can convert back to red marrow."

*Visual: doctor, lab, donor.*

Narration: "Diseases like leukemia and aplastic anemia affect bone marrow. Bone marrow tests and transplants can help diagnose and treal

Narration: "Red bone marrow is the body's blood factory, making the cells that carry oxygen, fight disease and stop bleeding."

- Site: spongy bone

- Function: formation of RBCs, WBCs, platelets

- Process: hematopoiesis

- Adults: flat bones and ends of long 🩻 

- Replaced by yellow marrow with age⁷