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Connective tissue
Question | Answer |
---|---|
what is the main structural unit of the connective tissue | the abundant extracellular matrix |
what is the abundant extracellular matrix made of | fibers and the ground substance |
what are the fibers in the extracellular matrix made of | collagen, elastin and reticular |
what is the gel made of | glycosaminglycans, proteoglycans, water and ions |
what are three things that in total, make up connective tissue | cells, fibers and the ground substance. |
what are the two major groups that connective tissue is divided into | ordinary and special connective tissue |
what are the subcategories underneath the "ordinary" division | loose, dense irregular and dense regular |
what is the subcategory underneath the "special" division | adipose tissue, cartilage tissue and bone tissue. |
what type of cell forms the extracellular matrix of ordinary connective tissue | fibroblast cells. |
what chemical does fibroblast cells secrete and in what form | they secrete collagen in the form of procollagen molecules. |
what happens to the procollagen molecules when the are free within the matrix | they join to form fibers. |
when procollagen molecules form thick bundles orientated in a number of different planes, what type of ordinary connective tissue do they form? | dense irregular connective tissue |
what type of tissue does the procollagen molecules form when whey they make fibers that run parallel to each other | dense regular connective tissue |
which type of tissue are fibroblasts most abundant in | ordinary connective tissue |
is bone considered to be a connective tissue | absolutely |
what is bone made of | cells and fibers that are embedded in a hard, mineralised substance. |
what is the main structural unit of bone | osteons |
what sheaths the inside and outside surfaces of bones | endosteum on the inside and periosteum on the outside. |
what are the two layers or periosteum | the outer protective fibrous layer and the inner cellular osteogenic layer |
what cells are within the osteogenic layer | osteoprogenitor cells |
what do osteoprogenitor cells mature into | osteoblast cells, which form the bone |
what does "osteoblasts synthesise the extracellular matrix" mean? | the osteoblast cells syntehsise the collagen fibers of the bone and teh ground substance of the bone which is called osteoid which is called prebone. |
what must be present to allow the bone to calcify | the local combined concentration of calcium and phosphate ions must reach a particular level that allow calcium phosphate deposition. |
what happens when matrix secretion is almost complete | the osteoblasts surround themselves with osteoid and they become osteocytes. |
what are osteocytes responsible for | they are responsible for maintaining the matrix of the bone |
what is the "pit" called that an osteocyte sits in | lacuna |
what is lamellar and what age of animal is it found in | it is found in aged animals and lamellar are a layer of collagen fibers that eventually form a ring pattern in the bones. |
what is found within an osteon | a series of concentric rings made from layers of bone matrix around a canal that has a blood vessel, lymph vessel and nerve travel |
where are osteocytes found | they are found been the concentric lamellae and maintain cell to cell contact |
what allows the transport of substances between the blood vessels in the canal and the bone matrix | the osteocytes |
what are osteoclasts | they are large, multi-nucleated motile cells, resorb surplus/inferior bone matrix. are needed for remodelling when there is bone repair or growth. also help with the removal of substranded/weakened matrix that must be replaced. |