(mar'ō )

1. 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 consists principally of fat cells and connective tissue and does not participate in hematopoiesis. Red marrow produces red blood cells.SYN: bone; medulla (1).

   SEE: illus.

2. The substance of the spinal cord. SYN: spinal marrow.
3. In acupuncture, the bone marrow, brain, and spinal cord. The form is usually marrows.

bone m.Marrow (1).

gelatinous m.Yellow marrow of the old or the emaciated, almost devoid of fat and having a gelatinous consistency.

spinal m.Marrow (2).

illus.