Cartilage- A Type Of Connective Tissue

Chondrocytes Cells that make up cartilage; synthesize and secrete the extra cellular matrix, located in matrix cavities called lacunae List three forms of Cartilage Hyaline Cartilage Elastic Cartilage Fibrocartilage Describe Hyaline Cartilage Hyaline Cartilage, the most common form of cartilage where type two collagen is the principle collagen type - bluish white and translucent - forms the primary skeleton of the fetus Describe Elastic Cartilage Elastic Cartilage is more pliable and distensible and posess an abundance of elastic fibers in addition to collagen type 2. - essentially identical to hyaline cartilage with the exception of thin elastic fibers. Describe Fibrocartilage Fibrocartilage is characterised by a matrix containing a dense network of coarse type one collagen fibers. - intermediate between dense connective tissue and hyaline cartilage. Perichondrium Perichondrium- a sheath of dense connective tissue that surrounds cartilage in most places forming an interface between the cartilage and the tissue it supports. Epiphseal plates Epiphseal plates or ends of long bones where hyaline cartilage is formed. Where can Hyaline Cartilage be found? Located in the articular surface of the movable joints, walls of the respiratory passages, in the ventral ends of ribs, where they articulate with the sternum and the epiphyseal plate. Describe the Matrix of hyaline cartilage. 40% of dry weight consists of collagen embedded in a firm, hydrated gel of proteoglycans and structural glycoprotiens.1 contains primarily type 2 collagen with small amounts of of collagen types 9, 10 & 11.2 Cartilage proteoglycans contain chondroitin 4 -sulphate, chondroitin 6- sulphate, covalently linked to core protiens. Proteoglycan aggregates are also found alongside Chondonectin. Proteoglycan aggregates long molecules of hyaluronic acidthat can be found associated with more than 200 proteoglycans. Chondronectin structural glycoprotien, that binds specifically to glycosaminoglycans and collagen type 2, mediating the adherence of chondrocytes to the extracellular matrix. Territorial / Capsular matrix the periferal zone of cartilage matrix surrounding each chondrocyte rich in glycosaminoglicans and collagen type 2 that stains differently from the rest of the matrix Describe Hyaline Perichondrium covers all hyline cartilage except that of the articular cartilage of joints. Essential for growth and maintenance of cartilage. Rich in collagen type 2 fibers and contains numerous fibroblasts. Chondrocytes Responsible for the synthesis of collagens and other matrix molecules. function depends on proper hormonal balance namely, somatotropin C produced in the liver. How do hormones influence the function of Chondrocytes? Synthesis of sulphated glycosaminoglycans is accelerated by growth hormone, thyroxin and testosterone and is slowed by cortisone, hydrocortisone, and estradiol. Describe processes attributable to growth of cartilage. - Interstitial growth, results from the mitotic division of preexisting chondrocytes - Appositional growth, results from the differentiation of perichondrial cells. Compare the processes of interstitial and appositional growth. - Interstitial growth, results from the mitotic division of preexisting chondrocytes - Appositional growth, results from the differentiation of perichondrial cells. Explain the poor rate of regeneration of cartilage tissue. with the exception of young children, damaged cartilage regenerates with difficulty and often incompletely, by the activity of the perichondrium. in excessively damaged areas the perichondrium produces a scar of dense connective tissue instead of forming new cartilage. Where can Elastic Cartilage be found? - found in the auricle of the ear, the walls of the external auditory canals, the auditory eustachian tubes, the epiglotis, and the cuniform cartilage in the larynx. - frequently found to be regularly continuous with hyaline cartilage. Where can fibro cartilage be found? is always associated with dense connective tissue Interverttebral disks, in attachment of certain ligaments to the cartilagenous surface of bones and in the symphysis pubis. How does the arrangement of fibro cartilage differ from other forms of cartilage? Contains chondrocytes, either singly or in isogenous groups, usually arranged in long rows seperated by coarse collagen type 1 fibers making the matrix acidophilic. -the numerous collagen fibers either form irregular bundles between the groups of chondrocytes or are aligned in parallel arangementalong the columns of chondrocytes. -orientation differs according to the stresses acting on fibro cartilage. Since Colagen bundles take up a direction parallel to those stresses. - there is no identifiable perichondrium in fibrocartilage. Annulus Fibrosus Component of intervertebral disks has an external layer of dense connective tissue, but is mainly composed of overlapping laminae of fibrocartilage in which collagen bundles are orthogonally arranged in adjacent layers. Nucleus pulposus Situated in the center of the annulus fibrosus. derived from the embryonic notochord and consists of a few rounded cells embedded in a viscous matrix rich in hyaluronic acid and type 2 collagen fibrils. - is large in children but gradually becomes smaller with age and is particularly replaced with fibro cartilage.