Where do you find CT?

What are the fibers in CT?

What cells hang out in CT?

Connective Tissue

Holding it all together!

Connective tissue is found everywhere! Main types:1. Connective tissue proper –

We will focus on this one most of next week!2. Cartilage3. Bone4. Blood

Properties

1. common origin Mesenchyme Mesenchyme is an embryonic tissueFrom the mesoderm

EctodermEndoderm

2. degrees of vascularity3. great degree of “non-living” extracellular

matrix What do we mean non-living?

Connective Tissue – essential functions

1. Binds structures 2. Provides support and protection 3. Insulation4. Transportation5. Energy storage

Structural elements:

1. Ground substance (matrix) 2. Fibers3. Cells

Wide range of varying tissue!Different structuresdifferent functions!

Ground Substance (matrix) Unstructured material Fills spaces/contains fibersComposed of:

1. interstitial fluid2. cell adhesion proteins glue like function3. Proteoglycansprotein core (point of

attachment) “GAGs” glycosaminoglycans 1. (interlock trapping water)

Major Cell Types: Blasts vs. Cytes

Fibroblasts- cells that produce fibers by secreting proteins into the matrix of CT tissue

Macrophages- originate as WBCs specialized cell phagocytosis

Mast Cells- release heparin prevents blood clotting, release histaminepromotes reactions associated with inflammation and allergies.

Fibroblast—laying matrix

http://www.usc.edu/hsc/dental/ghisto/ct/d_16.html

CONNECTIVE TISSUE-3 FIBER TYPESA. 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)

B. Elastic fibers-Composed of protein elastinThese fibers branch, forming complex

networks.weaker than collagenous fiber

however they stretch and can return back to there shape

Elastic Fibers

C. Reticular Fibers Very thin collagenous fibers Highly branched, form supporting

networks (LIKE A NET)

Reticular Fibers

When it comes to CT you can have a variety of types….Loose CT

1. areolar tissue2. Reticular tissue 3. Adipose tissue

DenseRegular Irregular Cartilage types

I.

Loose Connective Tissue Forms delicate thin membranes

throughout the bodyMain cellFibroblasts separated by a gel-

like matrix Binds skin to underlying organs and fills

spaces between musclesLies beneath epithelium

2

Adipose TissueFAT, 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.

3

Dense Connective Tissueregular or irregular

Closely packed, thick, collagenous fibers and a close network of elastic fibers. Relatively few cellsmost of which are fibroblasts.

VERY STRONG TISSUE

4

Cartilage Rigid CTprovides support, frameworks, and

attachments, protects underlying tissueforms structural models for developing bone.

Cartilage matrixabundant, largely composed of colagenous fibers embedded in a gel-like ground substance .

Cartilagea special case

SPECIAL CARTILAGE CELLSCHONDROCYTES, occupy small

chambers called lacunae

Cartilage structures are enclosed in a covering of CTperichondrium (contains the blood vessels that deliver nutrients)

THE INTERCELLULAR MATRIX DISTINGUISHES THE TYPE OF CARTILAGE!

Hyaline Cartilage

*most common type *very fine collagenous fibers (looks like white glass)

Location: end of bones, joints, soft part of nose, trachea

Elastic Cartilage

Dense network of elastic fibers Much more flexible than hyaline cartilage

Location: framework of ear, parts of larynx

Fibrocartilage

Tough tissue, contains many collagenous fibers

-shock absorber for structures subjected to pressure.

Location: vertebrae (discs), knees, pelvic girdle.