Bone marrow

Nonmineralized tissue found within bone containing hematopoietic and/or fatty tissues.

The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.

The soft tissue located in the cavities of the bones. The is the source of all blood cells.

Soft tissue found in the center of the spongy bone that stores fat and produces red and white blood cells and platelets.

Blood-producing tissue within the bones of the body, the factory for oxygen-carrying red blood cells, disease-fighting white blood cells, and platelets, important in blood-clotting. At birth, the most productive “red” bone marrow is present in all bones, but by adolescence it generally becomes confined to the large central bones, including the spine, skull, chest bone (sternum), ribs, shoulder bone (clavicle), shoulder blades (scapulae), and hip bones. Normally well protected in its bony housing, bone marrow can be affected by infections, as in osteomyelitis, or by tumors; it can also malfunction, producing too few of some blood cells, as in aplastic anemia, or too many, as in leukemia or polycythemia. In cases where bone marrow has been damaged, surgical removal of diseased marrow and replacement in a bone marrow transplant may be necessary.

Specialized soft tissue found within bone. Red bone marrow, widespread in the bones of children and found in some adult bones (e.g., sternum, ribs), is essential for the formation of mature red blood cells. Fat-laden yellow bone marrow, more common in adults, is found primarily at the ends of long bones.

A soft, organic material rich in blood vessels, found in the cavities and the spongy bone layer of most bones; also known as myeloid tissue. There are two types of bone marrow. Red marrow is the primary production site for blood cells, particularly red blood cells (erythrocytes) and certain kinds of white blood cells (granular leukocytes). Red marrow contains little fat. Yellow marrow gets its color from the large amount of fat it contains; it is usually found in the body’s long bones. It produces some types of white blood cells.

The tissue contained within the internal cavities of the bones. At birth, these cavities are filled entirely with blood-forming myeloid tissue (red marrow) but in later life the marrow in the limb bones is replaced by fat (yellow marrow). Samples of bone marrow may be obtained for examination by aspiration through a stout needle or by trephine biopsy.

Bone marrow is the soft substance occupying the interior of bones. It is the site of formation of erythrocytes, granular leucocytes and platelets.

The soft tissue in the marrow cavities of long bones (yellow marrow) and in the spaces between trabeculae of spongy bone in the sternum and other flat and irregular bones (red marrow). Yellow marrow is mostly fat, stored energy. Red marrow produces all the types of blood cells.

A layer of soft tissue at the center of many bones.

A porous tissue situated within flat bones, such as the hip, breastbone, and skull. This specialized tissue houses stem cells, which serve as the progenitors for platelets, red blood cells, and white blood cells.

The bone cavities house a soft and fatty tissue known as bone marrow, which can exhibit either a red or yellow appearance. Red bone marrow is initially present in all bones from birth and serves as the primary site for the production of most blood cells. As individuals enter their teenage years, certain bones gradually undergo a transition where the more active red marrow is replaced by less active yellow marrow. In adults, red marrow is predominantly restricted to specific locations including the spine, sternum (breastbone), pelvis (hip bones), ribs, scapulae (shoulder blades), clavicles (collarbones), and the bones of the skull.