Difference Between Red and Yellow Bone Marrow

Main Difference – Red Bone Marrow vs Yellow Bone Marrow

Red and yellow bone marrow are the two types of bone marrow that occur in animals. Red bone marrow occurs between the trabeculae of spongy bones. Yellow bone marrow occurs in the marrow cavity of the compact bones of the long bones. The main difference between red bone marrow and yellow bone marrow is that red bone marrow produces red blood cells, white blood cells, and platelets whereas yellow bone marrow produces fat cells, cartilage, and bones. Red bone marrow gets its color by hemoglobin in the red blood cells. Yellow bone marrow gets its color by carotenoids in the fat droplets. Both types of bone marrow are highly vascularized. At birth, all bone marrow is red. More and more red bone marrows are converted into yellow bone marrow with age.

Key Areas Covered

1. What is Red Bone Marrow
      – Definition, Characteristics, Function
2. What is Yellow Bone Marrow
      – Definition, Characteristics, Function
3. What are the Similarities Between Red and Yellow Bone Marrow
      – Outline of Common Features
4. What is the Difference Between Red and Yellow Bone Marrow
      – Comparison of Key Differences

Key Terms: Adipocytes, Compact Bones, Hematopoiesis, Marrow Cavity, Red Bone Marrow, Spongy Bones, Trabeculae, Yellow Bone Marrow

What is Red Bone Marrow

Red bone marrow is the bone marrow that contains the hematopoietic tissue. Red bone marrow produces red blood cells, most of the white blood cells, and platelets. At birth, all bone marrow is red. With age, red bone marrow is replaced by yellow bone marrow. In adults, red bone marrow can be identified in the spongy bones of the skull, ribs, spine, shoulder blades, sternum, and at the ends of the long bones in arms and legs. The spaces of the trabeculae plates in the spongy bones are filled with the red bone marrow.

Difference Between Red and Yellow Bone Marrow

Figure 1: Bone Marrow

The hematopoietic stem cells of the bone marrow produce two types of stem cells; lymphoid stem cells and myeloid stem cells. These stem cells are differentiated into red blood cells and white blood cells respectively at the red bone marrow. Therefore, red bone marrow consists of all developmental stages of most of the blood cells. After maturation, these blood cells are released into the circulation. The red bone marrow also serves as filters for damaged and aged blood cells and removes them from the circulation. Red and yellow bone marrow are shown in figure 1.

What is Yellow Bone Marrow

Yellow bone marrow is the bone marrow that is filled with fat. It mainly occurs in the marrow cavity of the long bones. The red bone marrow in the marrow cavity is replaced by the yellow bone marrow at the age of five years. The fat is stored in the adipocytes and can be used in extreme hunger. The fat in the yellow bone marrow is the last source of body’s energy. In situations like large blood loss, the yellow bone marrow is capable of converting to the red bone marrow to produce blood cells. Yellow bone marrow can also be converted into cartilage and compact bones.

Main Difference - Red vs Yellow Bone Marrow

Figure 2: Yellow Bone marrow in a Long Bone

Yellow bone marrow consists of a poor blood supply compared to the red bone marrow. The yellow bone marrow in a long bone is shown in figure 2.

Similarities Between Red and Yellow Bone Marrow

Red and yellow bone marrow are the two types of bone marrow found inside the bones.
Both red and yellow blood cells consist of cells, blood vessels, and capillaries.
In adults, red and yellow bone marrow are found in equal proportions.

Definition

Red Bone Marrow: Red bone marrow is a mesh of networks that contain the developmental stages of red blood cells, white blood cells, and megakaryocytes.

Yellow Bone Marrow: Yellow bone marrow is the bone marrow that primarily contains fat and replaces the red bone marrow in the long bones during adolescence.

Alternative Names

Red Bone Marrow: Red bone marrow is also known as medulla ossium rubra.

Yellow Bone Marrow: Yellow bone marrow is also known as medulla ossium flava.

Location in Bones

Red Bone Marrow: Red bone marrow occurs inside the spongy bones.

Yellow Bone Marrow: Yellow bone marrow occurs inside the compact bones.

Production

Red Bone Marrow: Red bone marrow produces red blood cells, white blood cells, and platelets.

Yellow Bone Marrow: Yellow bone marrow produces fat cells, cartilage, and bones.

Cells

Red Bone Marrow: The cells in the red bone marrow actively divide to produce blood cells.

Yellow Bone Marrow: The cells in the yellow bone marrow store fats; they also produce blood cells when needed.

Color

Red Bone Marrow: Red bone marrow gets its red color due to the hemoglobin present in the red blood cells.

Yellow Bone Marrow: Yellow bone marrow gets its yellow color due to the carotenoids in the fat droplets.

Development

Red Bone Marrow: Red bone marrow occurs throughout the skeleton during the fetal life.

Yellow Bone Marrow: With age, yellow bone marrow replaces the red bone marrow in long bones.

Location in the Skeleton

Red Bone Marrow: Red bone marrow occurs in the skull, ribs, spine, shoulder blades, and at the end of the long bones.

Yellow Bone Marrow: Yellow bone marrow occurs in the marrow cavity of the long bones.

Blood Supply

Red Bone Marrow: Red bone marrow is rich in blood supply.

Yellow Bone Marrow: Yellow bone marrow has a poor blood supply.

Conclusion

Red and yellow bone marrow are the two types of bone marrow found inside the bones. Red bone marrow occurs in the spaces between trabeculae of spongy bones. Yellow bone marrow occurs in the marrow cavity of the long bones. Red bone marrow produces blood cells while yellow bone marrow stores fat. The main difference between red and yellow bone marrow is the occurrence and function of the each type of bone marrow in the body.

Reference:

1. Bailey, Regina. “Bone Marrow Structure and Function.” ThoughtCo, Available here. Accessed 10 Sept. 2017.

Image Courtesy:

1. “619 Red and Yellow Bone Marrow” By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia
2. “Bone cross-section” By Pbroks13 – Own work (CC BY 3.0) via Commons Wikimedia