Connective tissue is found everywhere! Main types: 1. Connective tissue proper – We will focus on this one most of next week! 2. Cartilage 3. Bone 4. Blood
Properties 1. common origin Mesenchyme Mesenchyme is an embryonic tissue From the mesoderm Ectoderm Endoderm 2. degrees of vascularity 3. 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.Insulation 4.Transportation 5.Energy storage
Structural elements: 1.Ground substance (matrix) 2.Fibers 3.Cells Wide range of varying tissue! Different structures different functions!
Ground Substance (matrix) Unstructured material Fills spaces/contains fibers Composed of: 1.interstitial fluid 2.cell adhesion proteins glue like function 3.Proteoglycans protein 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 histamine promotes reactions associated with inflammation and allergies.
CONNECTIVE TISSUE-3 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)
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
When it comes to CT you can have a variety of types…. Loose CT 1.areolar tissue 2.Reticular tissue 3.Adipose tissue Dense Regular Irregular Cartilage types
I. Loose Connective Tissue 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
3 regular or irregular 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