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Osteoblast
Osteoblasts (from the Greek combining forms for " bone", ὀστέο-, ''osteo-'' and βλαστάνω, ''blastanō'' "germinate") are cells with a single nucleus that synthesize bone. However, in the process of bone formation, osteoblasts function in groups of connected cells. Individual cells cannot make bone. A group of organized osteoblasts together with the bone made by a unit of cells is usually called the osteon. Osteoblasts are specialized, terminally differentiated products of mesenchymal stem cells. They synthesize dense, crosslinked collagen and specialized proteins in much smaller quantities, including osteocalcin and osteopontin, which compose the organic matrix of bone. In organized groups of disconnected cells, osteoblasts produce hydroxyapatite, the bone mineral, that is deposited in a highly regulated manner, into the inorganic matrix forming a strong and dense mineralized tissue, the mineralized matrix. Hydroxyapatite-coated bone implants often perfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Mineral
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 tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue, a type of specialised connective tissue. It has a honeycomb-like matrix internally, which helps to give the bone rigidity. Bone tissue is made up of different types of bone cells. Osteoblasts and osteocytes are involved in the formation and mineralisation of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mineralised ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Tissue
A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provide structure and support for the body, and enable animal locomotion, 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 Function (biology), functions. Bone tissue (osseous tissue), which is also called bone in the mass noun, uncountable sense of that word, is hard tissue, a type of specialised connective tissue. It has a honeycomb-like matrix (biology), matrix internally, which helps to give the bone rigidity. Bone tissue is made up of different types of bone cells. Osteoblasts and osteocytes are involved in the formation and mineralization (biology), mineralisation of bone; osteoclasts are involved in the bone resorption, reso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone
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 tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue, a type of specialised connective tissue. It has a honeycomb-like matrix internally, which helps to give the bone rigidity. Bone tissue is made up of different types of bone cells. Osteoblasts and osteocytes are involved in the formation and mineralisation of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteopontin
Osteopontin (OPN), also known as bone /sialoprotein I (BSP-1 or BNSP), early T-lymphocyte activation (ETA-1), secreted phosphoprotein 1 (SPP1), 2ar and Rickettsia resistance (Ric), is a protein that in humans is encoded by the ''SPP1'' gene (secreted phosphoprotein 1). The murine ortholog is ''Spp1''. Osteopontin is a SIBLING (glycoprotein) that was first identified in 1986 in osteoblasts. The prefix '' osteo-'' indicates that the protein is expressed in bone, although it is also expressed in other tissues. The suffix ''-pontin'' is derived from “pons,” the Latin word for bridge, and signifies osteopontin's role as a linking protein. Osteopontin is an extracellular structural protein and therefore an organic component of bone. The gene has 7 exons, spans 5 kilobases in length and in humans it is located on the long arm of chromosome 4 region 22 (4q1322.1). The protein is composed of ~300 amino acids residues and has ~30 carbohydrate residues attached, including 10 sia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Remodeling
300 px, Bone tissue is removed by osteoclasts, and then new bone tissue is formed by osteoblasts. Both processes utilize cytokine ( Insulin-like_growth_factor.html" ;"title="TGF-β, Insulin-like growth factor">IGF) signalling. In osteology, bone remodeling or bone metabolism is a lifelong process where mature osseous tissue, bone tissue is removed from the skeleton (a process called ''bone resorption'') and new bone tissue is formed (a process called ''ossification'' or ''new bone formation''). Recent research has identified a specialised subset of blood vessels, termed Type R endothelial cells, in the bone microenvironment. These blood vessels play a crucial role in adult bone remodelling by mediating interactions between bone-resorbing osteoclasts and bone-forming osteoblasts. Type R blood vessels are characterised by their association with post-arterial capillaries and exhibit unique remodelling properties crucial for bone homeostasis. These processes also control the reshapin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Formation
Ossification (also called osteogenesis or bone mineralization) 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. In fracture healing, endochondral osteogenesis is the most commonly occurring process, for example in fractures of long bones treated by plaster of Paris, whereas fractures treated by open reduction and internal fixation with metal plates, screws, pins, rods and nails may heal by intramembranous osteogenesis. Heterotopic ossification is a process resulting in the formation of bone tissue that is often atypical, at an extraskeletal location. Calcification is often confused with ossification. Calcification is syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteocalcin
Osteocalcin, also known as bone gamma-carboxyglutamic acid-containing protein (BGLAP), is a small (49-amino-acid) noncollagenous protein hormone found in bone and dentin, first identified as a calcium-binding protein. Because osteocalcin has gla domains, its synthesis is vitamin K2-dependent. In humans, osteocalcin is encoded by the ''BGLAP'' gene. Its receptors include GPRC6A, GPR158, and possibly a third, yet-to-be-identified receptor. There is evidence that GPR37 might be the third osteocalcin receptor. Function Osteocalcin is secreted solely by osteoblasts and is thought to play a role in the body's metabolic regulation. In its carboxylated form, calcium is bound directly to the bone and thus concentrates here. In its uncarboxylated form, osteocalcin acts as a hormone in the body, signalling in the pancreas, fat, muscle, testes, and brain. * In the pancreas, osteocalcin acts on beta cells, causing beta cells in the pancreas to release more insulin. * In fat cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesenchymal Stem Cell
Mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells or medicinal signaling cells, are multipotent stromal cells that can Cellular differentiation, differentiate into a variety of cell types, including osteoblasts (bone cells), chondrocytes (cartilage cells), myocytes (muscle cells) and adipocytes (fat cells which give rise to Marrow Adipose Tissue, marrow adipose tissue). The primary function of MSCs is to respond to injury and infection by secreting and recruiting a range of biological factors, as well as modulating inflammatory processes to facilitate tissue repair and regeneration. Extensive research interest has led to more than 80,000 peer-reviewed papers on MSCs. Structure Definition Mesenchymal stem cells (MSCs), a term first used (in 1991) by Arnold Caplan at Case Western Reserve University, are characterized morphologically by a small cell body with long, thin cell processes. While the terms ''mesenchymal stem cell'' (MSC) and ''marrow stromal cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteon
In osteology, the osteon or haversian system (; named for Clopton Havers) is the fundamental functional unit of much compact bone. Osteons are roughly cylindrical structures that are typically between 0.25 mm and 0.35 mm in diameter. Their length is often hard to define, but estimates vary from several millimeters"Osteon," ''Encyclopædia Britannica Online'' (2009); retrieved 23 June 2009. to around 1 centimeter. They are present in many bones of most mammals and some bird, reptile, and amphibian species. Histogenesis The Haversian system forms during the process of endochondral ossification, which starts with a cartilage template that is gradually replaced by bone tissue. Osteoblasts, the bone-forming cells, secrete the organic components of bone matrix steoidand then initiates its mineralization. As osteoblasts become surrounded by the bone matrix, they differentiate into osteocytes, which reside in the lacunae and maintain bone tissue. The osteocytes connect to each o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeleton
A skeleton is the structural frame that supports the body of most animals. There are several types of skeletons, including the exoskeleton, which is a rigid outer shell that holds up an organism's shape; the endoskeleton, a rigid internal frame to which the organs and soft tissues attach; and the hydroskeleton, a flexible internal structure supported by the hydrostatic pressure of body fluids. Vertebrates are animals with an endoskeleton centered around an axial vertebral column, and their skeletons are typically composed of bones and cartilages. Invertebrates are other animals that lack a vertebral column, and their skeletons vary, including hard-shelled exoskeleton (arthropods and most molluscs), plated internal shells (e.g. cuttlebones in some cephalopods) or rods (e.g. ossicles in echinoderms), hydrostatically supported body cavities (most), and spicules (sponges). Cartilage is a rigid connective tissue that is found in the skeletal systems of vertebrates and invert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gap Junctions
Gap junctions are Membrane channel, membrane channels between adjacent cells that allow the direct exchange of cytoplasmic substances, such small molecules, substrates, and metabolites. Gap junctions were first described as ''close appositions'' alongside tight junctions, however, electron microscopy studies in 1967 led to gap junctions being named as such to be distinguished from tight junctions. They bridge a 2-4 nm gap between cell membranes. Gap junctions use protein complexes known as connexons, composed of connexin proteins to connect one cell to another. Gap junction proteins include the more than 26 types of connexin, as well as at least 12 non-connexin components that make up the gap junction complex or ''nexus,'' including the tight junction protein ZO-1—a protein that holds membrane content together and adds structural clarity to a cell, sodium channels, and aquaporin. More gap junction proteins have become known due to the development of next-generation sequencing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
