Connective Tissue

1. Connective Tissue Holding it all together!

2. Connective tissue is found everywhere! • Main types: • 1. Connective tissue proper – • We will focus on this one most of this week! • 2. Cartilage • 3. Bone • 4. Blood

3. Properties • 1. common origin Mesenchyme • Mesenchyme is an embryonic tissue • 2. degrees of vascularity • 3. great degree of “non-living” extracellular matrix • What do we mean non-living?

4. Connective Tissue • Binds structures • Provides support and protection • Insulation • Transportation

5. Structural elements: • Ground substance (matrix) • Fibers • Cells • Wide range of varying tissue! • Different structuresdifferent functions!

6. Ground Substance (matrix) • Unstructured material • Fills spaces/contains fibers • Composed of: • interstitial fluid • cell adhesion proteins glue like function • Proteoglycansprotein core (point of attachment) “GAGs” glycosaminoglycans • (interlock trapping water)

7. Major Cell Types: Blasts vs. Cytes • Fibroblasts- large star shaped cells that produce fibers by secreting proteins into the matrix of CT tissue • Macrophages- originate as white blood cells specialized cellphagocytosis • Mast Cells- release heparinprevents blood clotting, release histaminepromotes reactions associated with inflammation and allergies.

8. Fibroblast—laying matrix

13. CONNECTIVE TISSUE-FIBER TYPES • A. Collagenous fibers- Thick threads of protein (collagen) • Grouped in long parallel bundles, they are flexible, but only slightly elastic. • Great tensile strength (ligaments and tendons)

14. B. Elastic fibers- • Composed of protein elastin • These fibers branch, forming complex networks. • (weaker than collagenous fiber, however they stretch and can return back to there shape.)

15. Elastic Fibers

16. C. Reticular Fibers • Very thin collagenous fibers • Highly branched, form supporting networks • (LIKE A NET)

17. Reticular Fibers

18. When it comes to CT you can have a variety of types…. • Loose CT (areolar tissue) • Reticular tissue • Adipose tissue • Denseregular and irregular • Cartilage types

19. I. • Loose Connective Tissue • Forms delicate thin membranes throughout the body • Main cellFibroblasts separated by a gel-like matrix • Binds skin to underlying organs and fills spaces between muscles • Lies beneath epithelium

21. 2 • Adipose Tissue • FATspecialized form of CT, develop when certain cells store fat in droplets within their cytoplasm. • Beneath the skin, stored in many other locations as well. • Cushions, insulates, stores energy.

23. 3 • Dense Connective Tissueregular or irregular • Closely packed, thick, collagenous fibers and a close network of elastic fibers. Relatively few cellsmost of which are fibroblasts. • VERY STRONG TISSUE

26. 4 • Cartilage • Rigid CTprovides support, frameworks, and attachments, protects underlying tissue and forms structural models for developing bone. • Cartilage matrixabundant, largely composed of colagenous fibers embedded in a gel-like ground substance .

27. Cartilagea special case • SPECIAL CARTILAGE CELLS • CHONDROCYTES, occupy small chambers called lacunae

29. Cartilage structures are enclosed in a covering of CTperichondrium (contains the blood vessels that deliver nutrients) • THE INTERCELLULAR MATRIX DISTINGUISHES THE TYPE OF CARTILAGE! 

31. Hyaline Cartilage • *most common type • *very fine collagenous fibers • (looks like white glass) • Location: end of bones, joints, soft part of nose, trachea

32. Elastic Cartilage • Dense network of elastic fibers • Much more flexible than hyaline cartilage • Location: framework of ear, parts of larynx

35. Fibrocartilage • Tough tissue, contains many collagenous fibers • -shock absorber for structures subjected to pressure. • Location: vertebrae (discs), knees, pelvic girdle.