Composition of Connective Tissue in Tamil | biomechanics| collagen and elastin in Tamil| скачать в хорошем качестве

Composition of Connective Tissue in Tamil | biomechanics| collagen and elastin in Tamil|

composition of Connective tissue in tamil composition of Connective tissue biomechanics. Notes : Composition of Connective Tissue The joint structures that are all composed of connective tissues, including bones, bursae, capsules, cartilage, discs, labrums, menisci, plates, ligaments, and tendons. Connective tissues are characterized by widely dispersed cells and a large volume of extracellular matrix. extracellular matrix has both interfibrillar (also known as the ground substance) and fibrillar (fibrous) components . Cells : The cells of all connective tissues function primarily to synthesize the extracellular matrix of connective tissues. The fibroblast is the basic cell of most connective tissues. Depending on its mechanical and physiological environment fibroblasts may specialize to become osteoblstast, chondroblasts , tendoblast cells are called chondrocytes, tenocytes, and osteocytes . Extracellular Matrix : The extracellular matrix is the part of connective tissues outside the cells. It determines the tissue's function. The extracellular matrix primarily contains proteins and water and is organized into its fibrillar and surrounding interfibrillar components FIBRILLAR COMPONENT The fibrillar, or fibrous, component of the extracellular matrix contains two major classes of structural proteins: collagen and elastin." Collagen : Collagen, the main substance of most connective tissues, is found in all multicellular organisms. The most abundant protein in the human body, it accounts for 25% to 30% of all protein in mammals." Collagen has a tensile strength similar to steel and is responsible for the functional integrity of connectivé tissue structures and the resistance of connective tissue to tensile forces. Many types of collagen have been identified, but the functions of many are not yet well understood. The fibril-forming collagens (types I, II, and III) are the most common. Type I collagen accounts for 90% of the total collagen in the body and is found in most connective tissues, including tendons, ligaments, menisci, fibrocartilage, joint capsules, synovium, bones, labrums, and skin. Elastin : Elastin also is found in many connective tissues but, unlike collagen, the molecule consists of single alpha-like strands without a triple helix The alpha-like stranda are cross-linked to each other to form rubber-like elastic fibers. Each elastin molecule uncoils into a more extended formation when the fiber is stretched then recoils spontaneously when the stretching forces is removed . Elastin fibers branch freely and are found in all joint structures including the skin, the tracheobronchial tree, and the walls of arteries. Elastin makes up a much smaller portion of the fibrous component in the extracellular matrix than does collagen. As one might expect, tissues that require "give" contain more elastin. The aorta contains approximately 30% elastin and 20% collagen (percentage of the tissue dry weight), the ligamentum nu-chae of the cervical spine has 75% elastin and 15% collagen, whereas the Achilles tendon contains only 4.4% elastin and 86% collagen. INTERFIBRILLAR COMPONENT The interfibrillar component of connective tissue, often referred to as the ground substance,contains primarily water and proteins called proteoglycans (PGs) with attached glycosaminoglycans (GAGs) . A PG can contain up to approximately 100 GAGs, which stick out from its protein core to form a shape like a bottle brush. 1.One large cartilage PG is called aggrecan.It has sugar chains (GAGs) attached to it, like chondroitin sulfate and keratan sulfate. 2.Aggrecan sticks to hyaluronan (a long sugar chain) with the help of link proteins. This forms large structures that hold water in the cartilage. 3. Water keeps cartilage soft yet strong, helping it absorb shocks and resist pressure. 4. Osteoarthritis Treatments: Some GAGs (hyaluronan, chondroitin sulfate, glucosamine) are used as supplements or injections for joint pain. However, they may not work well according to studies. PGs store nutrients and growth factors, which help tissues repair and grow.