Connective Tissue Flashcards
What produces the extracellular matrix (ECM)?
Produced by CT
What is the ECM?
Structural fibers; glycoproteins; and polysaccharides. Distinct for each type of CT. Largely determine structure and function of each tissue
Why is CT important?
Mechanical strength. Control exchange of nutrients/ligands. Control the ECM.
What is function of ECM
Control of epithelial cell polarization/shape. Guidance and regulation of cell migration through matrix. Controlcell proliferation; differentiation; metabolism. Defense/immune response/inflammation. Control tissue formation; organization; modification
What are mesenchymal cells?
Precursors to all of the connective tissue family members; primarily function in embryogenesis but small numbers of them may persist through adulthood to function as stem cells for generation of new connective tissues.
What are fibroblasts?
Pre-eminent cells of most connective tissues in the body
What are myofibroblasts?
Derivatives of fibroblasts that are capable of smooth muscle-like function and are found in connective tissues that require a contractile function. Often generated at the site of wounds where their contractile function contributes to retraction and shrinkage of scar tissue.
What are adipocytes?
Derivatives of fibroblasts and/or primitive mesenchymal cells. The main type of adipocyte found in adults functions to store fat as energy for other cell types; tissue containing these cells is called �white fat�. A distinct type of adipocyte is prominent in newborns/children; it contains many mitochondria that convert fatty acid into heat. Tissue with these cells is called �brown fat�.
What are osteoblasts and osteocytes?
Cells that make bone
What are chondrocytes?
Cells that make cartilage
What do smooth muscles cells do with respect to the ECM?
Some (esp. those in the walls of blood vessels) make some of the extracellular matrix components in which they are imbedded. Some smooth muscle cells derive from the same types of precursors as other connective tissue cells (why they can synthesize and secrete similar types of ECM components).
What are the immigrant blood-derived cells that are abundant in the CT?
Lymphocytes; macrophages; neutrophils/eosinophils; mast cells; osteoclasts
What are lymphocytes important for?
Central to acquired immunity to foreign organisms/viruses/materials.
What are macrophages?
Large phagocytotic cells. Engulf cells ECM; non-cellular material. Critical regulatory cells that secrete and respond to numerous extracellular signals. They can signal to stimulate endothelial cells to induce angiogenesis; immune cell migration and function; fibroblast activation; blood vessel permeability et al.
What are neutrophils and eosinophils important for?
Defense against microorganisms
What are mast cells important for? What are they derived from?
Secretory cells that (when stimulated by immune responses) release various substances including vasodilators that promote swelling in connective tissue; thus mast cells are important in edema and allergic hypersensitivities. Derived from basophils.