| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 3,897,794,973 visitors served. |
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
collagen |
Also found in: Dictionary/thesaurus, Encyclopedia, Wikipedia | 0.01 sec. |
|
|
collagen /col·la·gen/ (kol´ah-jen) any of a family of extracellular, closely related proteins occurring as a major component of connective tissue, giving it strength and flexibility; composed of molecules of tropocollagen.collag´enous
Collagen The main supportive protein of cartilage, connective tissue, tendon, skin, and bone. Mentioned in: Ehlers-Danlos Syndrome, Epidermolysis Bullosa, Osteogenesis Imperfecta, Scleroderma, Skin Grafting
collagen [kol′əjən] Etymology: Gk, kolla, glue, genein, to produce a fibrous insoluble protein consisting of bundles of tiny reticular fibrils that combine to form the white glistening inelastic fibers of the tendons, the ligaments, and the fascia. It is found in connective tissue, including skin, bone, ligaments, and cartilage. It represents 30% of total body protein. collagenous, adj. collagen [kol´ah-jen] any of a family of extracellular, closely related proteins occurring as a major component of connective tissue, giving it strength and flexibility. Numerous types exist, each composed of tropocollagen units that share a common triple-helical shape but that vary somewhat in composition between types, with the types being localized to different tissues. adj., adj collag´enous. collagen diseases a group of diseases having in common certain clinical and histological features that are manifestations of involvement of connective tissue, i.e., those tissues that provide the supportive framework (musculoskeletal structures) and protective covering (skin and mucous membranes and vessel linings) for the body.
The basic components of connective tissue are cells and extracellular protein fibers embedded in a matrix or ground substance of large carbohydrate molecules and carbohydrate-protein complexes called mucopolysaccharides. For the sake of clarity and organization, collagen diseases may be divided into two major groups: (1) those that are genetically determined and are a result of structural and biochemical defects, and (2) those that are acquired and in which immunological and inflammatory reactions are taking place within the tissues. Among the first group are those diseases caused by a lack of a specific enzyme necessary for proper storage and excretion of one or more mucopolysaccharides. Also included in this group are osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan's syndrome. These disorders are distinguished by structural defects affecting the formation of the extracellular fibers called collagen. Acquired connective tissue diseases are believed to develop as a result of at least two causative factors: a genetic factor and an abnormal immunological response. The exact role of these factors in the development of connective tissue diseases has not been firmly established, but there is strong evidence that immunological mechanisms are involved. Examples of collagen diseases that are most probably the result of an aberration of the immunological reactions that mitigate injury and inflammation of connective tissues are systemic lupus erythematosus, scleroderma, rheumatoid arthritis, rheumatic fever, polymyositis, and dermatomyositis. collagen, n protein that is the major constituent of cartilage and other connective tissue; comprises the amino acids hydroxyproline, proline, glycine, and hydroxylysine.
collagen (kol´ n an intercellular constituent of connective tissue and bone consisting of bundles of tiny reticular fibrils, most noticeable in the white, glistening, inelastic fibers of tendons, ligaments, and fascia.
collagen a fibrous structural protein that constitutes the protein of the white fibers (collagenous fibers) of skin, tendon, bone cartilage and all other connective tissues. It also occurs dispersed in a gel to provide stiffening, as in the vitreous humor of the eye. It is made of monomers of tropocollagen. Different types of collagen (types I, II, III, IV and V and others) occur in different locations and have differing chemical compositions and physical characteristics. collagen diseases a group of diseases having in common certain clinical and histological features that are manifestations of involvement of connective tissue, i.e. those tissues that provide the supportive framework (musculoskeletal structures) and protective covering (skin and mucous membranes and vessel linings) for the body. The basic components of connective tissue are cells and extracellular protein fibers embedded in a matrix or ground substance of large carbohydrate molecules and carbohydrate-protein complexes called mucopolysaccharides. For the sake of clarity and organization, collagen diseases may be divided into two major groups: (1) those that are genetically determined and are a result of structural and biochemical defects, and (2) those that are acquired and in which immmunological and inflammatory reactions are taking place within the tissues. Among the first group are those diseases caused by a lack of a specific enzyme necessary for proper storage and excretion of one or more mucopolysaccharides, such as Ehlers-Danlos syndrome. These disorders are distinguished by structural defects affecting the formation of collagen. Acquired connective tissue diseases are believed to develop as a result of at least two causative factors: a genetic factor and an abnormal immunological response. Examples of collagen diseases that are most probably the result of an aberration of the immunological reactions that mitigate injury and inflammation of connective tissues are systemic lupus erythematosus, rheumatoid arthritis, polymyositis and dermatomyositis. collagen dysplasia see hereditary collagen dysplasia. collagen fascicles interspersed with patches of cartilage in fibrous cartilage (fibrocartilage). collagen fibers the principal component of connective tissue, providing strength and resisting stretching; a structural protein in fiber form. collagen fibrils collagen fibers are composed of fibrils visible only by electron microscope. collagen footpad disorder footpads in young German shepherd dogs become soft, tender, depigmented and ulcerated. Some dogs later develop renal amyloidosis. The cause is unknown. microcrystalline collagen a surface hemostatic agent. collagen nevus see nevus. collagen sponge surgical sponge made of collagen; used to fill surgical space and to control hemorrhage. Is not absorbable but has enormous fluid absorption capacity and has excellent wet strength and is very pliable and easy to use. collagen suture
an absorbable suture of natural material; made from bovine flexor tendon. May be plain or chromic. collagen The major protein of the white fibres of connective tissue, cartilage, tendons and bones. It is strong, fibrous, insoluble in water, rich in glycine and proline and can be hydrolysed into gelatin by boiling. In the eye it forms the primary structural component of the cornea, lens capsule, ciliary body, vitreous base and sclera. Collagen material is also used to make punctal occlusion plugs used to treat keratoconjunctivitis sicca, and dissolvable therapeutic contact lenses to deliver high-dose drugs to the cornea. Mutations in collagen genes are a common cause of connective tissue disorders. See connective tissue disorders; punctal occlusion. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
|
| Medical Dictionary |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup |
|---|