bone marrow

(noun)

The fatty vascular tissue that fills the cavities of bones; the place where new blood cells are produced.

Related Terms

Examples of bone marrow in the following topics:

  • Bone Marrow Examination

    • In patients with suspected peripheral blood or bone marrow diseases, a bone marrow biopsy can isolate bone marrow for an examination.
    • Bone marrow examination is the pathologic analysis of samples of bone marrow obtained by bone marrow biopsy and bone marrow aspiration.
    • This is the purpose of bone marrow aspiration and biopsy.
    • There are few contraindications to bone marrow examination.
    • A bone marrow biopsy procedure consists of inserting a large-gauge syringe into an area of the hip and extracting the bone marrow.

  • RBC Life Cycle

    • Erythrocytes are continuously produced in the red bone marrow of large bones at a rate of about 2 million cells per second in a healthy adult.
    • Erythrocytes differentiate from erythrotropietic bone marrow cells, a type of hemopoietic stem cell found in bone marrow.
    • Unlike mature RBCs, bone marrow cells contain a nucleus.
    • Just before and after leaving the bone marrow, the developing cells are known as reticulocytes.
    • The bilirubin is excreted through the digestive system in the form of bile, while some of the iron is released into the plasma to be recirculated back into the bone marrow by a carrier protein called transferrin. 

  • Leukemia

    • Children with acute leukemia may be candidates for bone marrow transplants.
    • She later provided bone marrow for a transplant for her older sister.
    • Crowding due to such cells makes the bone marrow unable to produce healthy blood cells.
    • In some cases, a bone marrow transplant is useful.
    • A Wright's stained bone marrow aspirate smear of patient with precursor B-cell acute lymphoblastic leukemia.

  • Development of the Skeleton

    • It is synonymous with bone tissue formation.
    • This serves as support for the new bone.
    • This creates cavities within the bone.
    • The hemopoietic cells will later form the bone marrow.
    • Osteoclasts, formed from macrophages, break down spongy bone to form the medullary (bone marrow) cavity.

  • Microscopic Anatomy of Bone

    • The basic microscopic unit of bone is an osteon, which can be arranged into woven bone or lamellar bone.
    • Osteons can be arranged into woven bone or lamellar bone.
    • Woven bone is replaced by lamellar bone during development.
    • Lamellar bone makes up the compact or cortical bone in the skeleton, such as the long bones of the legs and arms.
    • The spaces within trabecular bone are filled with active bone marrow.

  • Overview of the Musculoskeletal System

    • Located in long bones are two distinctions of bone marrow: yellow and red.
    • The yellow marrow has fatty connective tissue and is found in the marrow cavity.
    • In times of starvation, the body uses the fat in yellow marrow for energy.
    • The red marrow of some bones is an important site for hematopoeisis or blood cell production: approximately 2.6 million red blood cells per second, in order to replace existing cells that have been destroyed by the liver.
    • Muscles keep bones in place and also play a role in movement of the bones.

  • Bone Repair

    • When the humerus in the upper arm is fractured and properly set, bone healing can repair the bone.
    • The bone marrow (when present), endosteum, small blood vessels, and fibroblasts are other sources of precursor cells.
    • Substitution of the woven bone with lamellar bone precedes the substitution of the hyaline cartilage with lamellar bone.
    • This new lamellar bone is in the form of trabecular bone.
    • The remodeling process substitutes the trabecular bone with compact bone.

  • Gross Anatomy

    • All the bones in the body can be described as long bones or flat bones.
    • There are two general types of bone: long bones and flat bones.
    • The outer shell of the long bone is compact bone, below which lies a deeper layer of cancellous bone (spongy bone) as shown in .
    • The interior part of the long bone is called the medullary cavity with the inner core of the bone cavity being composed of yellow marrow in adults, and red marrow in young children.
    • Flat bones are composed of two thin layers of compact bone surrounding a layer of cancellous (spongy) bone.

  • Paget's Disease

    • Paget's disease is a chronic bone disorder that causes affected bones to become large and misshapen.
    • Paget's disease of bone is a chronic disorder that can result in enlarged and misshapen bones .
    • The excessive breakdown and formation of bone tissue causes affected bone to weaken, resulting in pain, misshapen bones, fractures, and arthritis in the joints near the affected bones.
    • The resorbed bone is replaced and the marrow spaces are filled by an excess of fibrous connective tissue with a marked increase in blood vessels, causing the bone to become hypervascular.
    • The bone hypercellularity may then diminish, leaving a dense "pagetic bone," also known as burned-out Paget's disease .

  • Postnatal Bone Growth

    • It forms the epiphyses of long bones and the extremities of irregular and flat bones.
    • 1) Zone of reserve cartilage: This region, farthest from the marrow cavity, consists of typical hyaline cartilage that currently shows no sign of transforming into bone.
    • 2) Zone of cell proliferation: A little closer to the marrow cavity, chondrocytes multiply and arrange themselves into longitudinal columns of flattened lacunae.
    • This converts each column into a longitudinal channel, which is immediately invaded by blood vessels and marrow from the marrow cavity.
    • Newly formed bonee.