Definition

Noun: * Yellow marrow: A type of bone marrow that is yellow in color due to its high fat content. It is primarily composed of adipose (fat) cells and is found in the central cavities of long bones in adults.

Usage

Yellow marrow serves as a fat storage site within the skeletal system. In adults, it is the predominant type of marrow found in the shafts (medullary cavities) of long bones, such as those in the arms and legs. It can convert back to red marrow (which produces blood cells) in cases of severe blood loss or anemia.

Examples

• The biopsy showed that the yellow marrow in the femur was normal.
• With age, yellow marrow gradually replaces much of the red marrow in the skeletal system.
• The primary function of yellow marrow is fat storage.

Advanced Usage

• Medical Context: In radiology, yellow marrow has a distinct appearance on MRI scans due to its fat content, which helps differentiate it from red marrow or pathological conditions.
• Hematopoiesis: While yellow marrow is not actively hematopoietic (blood-forming) under normal conditions, it retains the potential to revert to red marrow and produce blood cells if the body requires it.

Variants and Related Words

• Bone Marrow (n): The soft, spongy tissue found inside bones. It exists as two main types: red marrow and yellow marrow.
• Red Marrow (n): The type of bone marrow responsible for producing red blood cells, white blood cells, and platelets. It is found in flat bones (like the hip and sternum) and the ends of long bones.
• Medullary Cavity (n): The central cavity of bone shafts where yellow marrow is stored.

Synonyms

• Fatty marrow
• Yellow bone marrow

Antonyms

• Red marrow
• Hematopoietic marrow

Noun

1. bone marrow that is yellow with fat; found at the ends of long bones in adults