A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple functions.
Bone marrow is a semi-solid tissue found within the spongy portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production. It is composed of hematopoietic cells, marrow adipose tissue, and supportive stromal cells. In adult humans, bone marrow is primarily located in the ribs, vertebrae, sternum, and bones of the pelvis. Bone marrow comprises approximately 5% of total body mass in healthy adult humans, such that a man weighing 73 kg (161 lbs) will have around 3.7 kg (8 lbs) of bone marrow.
An epiphysis is one of the rounded ends or tips of a long bone that ossify from a secondary center of ossification. Between the epiphysis and diaphysis lies the metaphysis, including the epiphyseal plate. At the joint, the epiphysis is covered with articular cartilage; below that covering is a zone similar to the epiphyseal plate, known as subchondral bone.
The human musculoskeletal system is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system provides form, support, stability, and movement to the body.
Erythropoiesis is the process which produces red blood cells (erythrocytes), which is the development from erythropoietic stem cell to mature red blood cell.
The long bones are those that are longer than they are wide. They are one of five types of bones: long, short, flat, irregular and sesamoid. Long bones, especially the femur and tibia, are subjected to most of the load during daily activities and they are crucial for skeletal mobility. They grow primarily by elongation of the diaphysis, with an epiphysis at each end of the growing bone. The ends of epiphyses are covered with hyaline cartilage. The longitudinal growth of long bones is a result of endochondral ossification at the epiphyseal plate. Bone growth in length is stimulated by the production of growth hormone (GH), a secretion of the anterior lobe of the pituitary gland.
The medullary cavity is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow is stored; hence, the medullary cavity is also known as the marrow cavity.
Endochondral ossification is one of the two essential processes during fetal development of the mammalian skeletal system by which bone tissue is produced. Unlike intramembranous ossification, the other process by which bone tissue is produced, cartilage is present during endochondral ossification. Endochondral ossification is also an essential process during the rudimentary formation of long bones, the growth of the length of long bones, and the natural healing of bone fractures.
The metaphysis is the neck portion of a long bone between the epiphysis and the diaphysis. It contains the growth plate, the part of the bone that grows during childhood, and as it grows it ossifies near the diaphysis and the epiphyses. The metaphysis contains a diverse population of cells including mesenchymal stem cells, which give rise to bone and fat cells, as well as hematopoietic stem cells which give rise to a variety of blood cells as well as bone-destroying cells called osteoclasts. Thus the metaphysis contains a highly metabolic set of tissues including trabecular (spongy) bone, blood vessels, as well as Marrow Adipose Tissue (MAT).
Ossification in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in the formation of normal, healthy bone tissue: Intramembranous ossification is the direct laying down of bone into the primitive connective tissue (mesenchyme), while endochondral ossification involves cartilage as a precursor.
The Divje Babe flute, also called tidldibab, is a cave bear femur pierced by spaced holes that was unearthed in 1995 during systematic archaeological excavations led by the Institute of Archaeology of the Research Centre of the Slovenian Academy of Sciences and Arts, at the Divje Babe I near Cerkno in northwestern Slovenia. It has been suggested that it was made by Neanderthals as a form of musical instrument, and became known as the Neanderthal flute. The artifact is on prominent public display in the National Museum of Slovenia in Ljubljana as a Neanderthal flute. As such, it would be the world's oldest known musical instrument.
Infantile cortical hyperostosis (ICH) is a self-limited inflammatory disorder of infants that causes bone changes, soft tissue swelling and irritability. The disease may be present at birth or occur shortly thereafter. The cause is unknown. Both familial and sporadic forms occur. It is also known as Caffey disease or Caffey's disease.
An ossification center is a point where ossification of the cartilage begins. The first step in ossification is that the cartilage cells at this point enlarge and arrange themselves in rows.
Myelophthisic anemia is a severe type of anemia found in some people with diseases that affect the bone marrow. Myelophthisis refers to the displacement of hemopoietic bone-marrow tissue by fibrosis, tumors, or granulomas. The word comes from the roots myelo-, which refers to bone marrow, and phthysis, shrinkage or atrophy.
Arthritis mutilans is a rare medical condition involving severe inflammation damaging the joints of the hands and feet, and resulting in deformation and problems with moving the affected areas; it can also affect the spine. As an uncommon arthropathy, arthritis mutilans was originally described as affecting the hands, feet, fingers, and/or toes, but can refer in general to severe derangement of any joint damaged by arthropathy. First described in modern medical literature by Marie and Leri in 1913, in the hands, arthritis mutilans is also known as opera glass hand, or chronic absorptive arthritis. Sometimes there is foot involvement in which toes shorten and on which painful calluses develop in a condition known as opera glass foot, or pied en lorgnette.
Ghosal hematodiaphyseal dysplasia, is a rare, autosomal recessive disease, characterized by diaphyseal dysplasia and metaphyseal dysplasia of the long bones and refractory anemia.
Bone marrow failure occurs in individuals who produce an insufficient amount of red blood cells, white blood cells or platelets. Red blood cells transport oxygen to be distributed throughout the body's tissue. White blood cells fight off infections that enter the body. Bone marrow also contains platelets, which trigger clotting, and thus help stop the blood flow when a wound occurs.
A unicameral bone cyst, also known as a simple bone cyst, is a cavity filled with a yellow-colored fluid. It is considered to be benign since it does not spread beyond the bone. Unicameral bone cysts can be classified into two categories: active and latent. An active cyst is adjacent to the epiphyseal plate and tends to grow until it fills the entire diaphysis, the shaft, of the bone; depending on the invasiveness of the cyst, it can cause a pathological fracture or even destroy the epiphyseal plate leading to the permanent shortening of the bone.
A nucleated red blood cell (NRBC), also known by several other names, is a red blood cell that contains a cell nucleus. Almost all vertebrate organisms have hemoglobin-containing cells in their blood, and with the exception of mammals, all of these red blood cells are nucleated. In mammals, NRBCs occur in normal development as precursors to mature red blood cells in erythropoiesis, the process by which the body produces red blood cells.
Sagol, or beef leg bone, is an ingredient in Korean cuisine. Sagol is often boiled to make a broth, called sagol-yuksu, or beef leg bone broth, for Korean soups such as gomguk, galbi-tang, tteokguk, kal-guksu, or gukbap.
