Connective tissue is found throughout the body and binds tissues together. It has various types including connective tissue proper, fluid connective tissue, and supportive connective tissue. Connective tissue proper contains fibroblasts, macrophages, mast cells, and an extracellular matrix with ground substance and fibers like collagen, elastic, and reticular fibers. It includes areolar, adipose, dense, and reticular connective tissues. Fluid connective tissue includes blood with its fluid plasma and blood cells. Supportive connective tissues are bone, hyaline cartilage, elastic cartilage, and fibrocartilage which provide structure and support.

1. TissuesChapter 3.3Connective Tissue

2. Connective TissueVariations in blood supplySome tissue types are well vascularizedSome have poor blood supply or are avascularHave receptors forPain, pressure, temperatureExtracellular matrixNon-living material that surrounds living cellsFound everywhere in the bodyNever exposed to the outside environmentIncludes the most abundant and widely distributed tissuesFunctionsBinds body tissues togetherSupports the bodyProvides protectionTransports materials

3. Extracellular MatrixTwo main elementsGround substance – mostly water along with adhesion proteins and polysaccharide moleculesFibersProduced by the cellsThree typesCollagen fibersElastic fibersReticular fibersThe combination of and the type of the two elements determines the connective tissue typeConnective tissue properFluid connective tissueSupporting connective tissue

4. Connective Tissue ProperMany types of cells, fibers and syrupy ground substanceFibroblastsLarge, star-shaped cell that produces fibers by secreting proteins into the matrixMacrophagesFunction as defensive cells, clearing foreign particlesMast cellsBegin body’s defense actions after injury or infectionMatrixGround substanceSyrupy, clear, colorlessFibersCollagen fibers - strong and flexibleElastic fibers - stretches, but returns to original lengthReticular fibers - interwoven networkExamplesSkinFatty tissueTendons and ligaments

5. Types Connective Tissue ProperAreolar connective tissueMost widely distributed connective tissueSoft, pliable tissue (Cobweb-like)

6. Types Connective Tissue ProperAreolar connective tissueMost widely distributed connective tissueSoft, pliable tissue (Cobweb-like)Contains all fiber typesCan soak up excess fluidCusions and protects body organsSeparates from and attaches skin to muscles

7. Types Connective Tissue ProperAdipose tissueMatrix is an areolar tissue fat globules stored in cytoplasmMany cells contain large lipid deposits

8. Types Connective Tissue ProperAdipose tissueMatrix is an areolar tissue fat globules stored in cytoplasmMany cells contain large lipid depositsFunctionsInsulates the bodyProtects some organsServes as a site of fuel storage

9. Types Connective Tissue ProperDense connective tissueMain matrix element is collagen fibers closely packedCells are fibroblasts

10. Types Connective Tissue ProperDense connective tissueMain matrix element is collagen fibers closely packedCells are fibroblastsExamplesTendon – attach muscle to boneLigaments – attach bone to bone

11. Types Connective Tissue ProperReticular connective tissueDelicate network of interwoven fibers

12. Types Connective Tissue ProperReticular connective tissueDelicate network of interwoven fibersForms stroma (internal supporting network) of lymphoid organsLymph nodesSpleen and liverBone marrow

13. Fluid Connective TissueBloodBlood cells (red, white, platelets) surrounded by fluid matrix (blood plasma)Fibers are visible during clottingFigure 3.19h

14. Fluid Connective TissueBloodBlood cells (red, white, platelets) surrounded by fluid matrix (blood plasma)Fibers are visible during clottingFunctions as the transport vehicle for materialsFigure 3.19h

15. Type Supportive Connective TissueBone (osseous tissue)Hardest of connective tissuesFunctionsUsed to protect and support the bodyForms “levers” for movementForms red blood cellsStores calcium and phosphorus

16. Type Supportive Connective TissueBone (osseous tissue)Hardest of connective tissuesFunctionsUsed to protect and support the bodyForms “levers” for movementForms red blood cellsStores calcium and phosphorusComposed of:Bone cells (osteocytes) in lacunae (cavities)Hard matrix of calcium phosphate saltsLarge numbers of collagen fibers

17. Type Supportive Connective TissueHyaline cartilageMost common cartilageFound on ends of bones in jointsSoft part of noseSupporting rings in respiratory passagesEntire fetal skeleton

18. Type Supportive Connective TissueHyaline cartilageMost common cartilageFound on ends of bones in jointsSoft part of noseSupporting rings in respiratory passagesEntire fetal skeletonComposed of:Abundant, very fine collagen fibersRubbery matrix

19. Type Supportive Connective TissueElastic cartilageDense network of elastic fibersMore flexible than hyaline cartilage

20. Type Supportive Connective TissueElastic cartilageDense network of elastic fibersMore flexible than hyaline cartilageProvides elasticity and supportFoundExternal earEpiglottisParts of larynx

21. Type Supportive Connective TissueFibrocartilageHighly compressible and very toughExamplesCushion-like discs between vertebraeCushions bones in knees and pelvic girdle