Types of Connective Tissue

1) Areolar (loose) Connective Tissue Fxn: wraps & cushions organs, holds tissue fluids, macrophages engulfs bacteria Cells: mainly fibroblasts (far apart), macrophages, mast cells and some WBC’s Matrix: gel-like w/ collagenous & elastic fibers (some reticular fibers) Location: beneath skin, b/w muscles, beneath epithelial tissues

2) Adipose Tissue Fxn: protection, insulation, storage Cells: enlarged; fat droplets push nucleus to side Matrix: as in aerolar, but sparse Location: beneath skin, around kidneys, behind eyeball, surface of heart, breasts “signet ring cells”

3) Reticular Connective Tissue Fxn: fibers form soft internal skeleton that supports other cell types Cells: reticular cells (fibroblasts), phagocytic (mainly macrophages), lymphocytes Matrix: reticular fibers in loose ground substances Location: bone marrow, spleen, lymph nodes “net-like”

4) Dense Regular Connective Tissue Fxn: binds organs together (very strong) Cells: relatively few (all fibroblasts) Matrix: many parallel collagenous fibers & fine network of elastic Location: tendons – (muscle to bone), ligaments – (bone to bone), sclera (white of eye) ** poor blood supply, therefore heals slowly** Aka: Fibrous CT

5) Dense Irregular Connective Tissue Fxn: able to withstand tension exerted in many directions; provides structural strength Cells: fibroblast Matrix: irregularly arranged collagenous fibers, some elastic Location: dermis of skin, digestive tract, fibrous joint capsules

6) Cartilage Fxn: rigid support, framework Cells: chondrocytes in small chambers (lacunae) Matrix: collagenous fibers embedded in gel-like substance (sometimes elastic)

6) Cartilage cont. Types Hyaline: fine collagen fibers; found on ends of bones, end of nose, support rings of respiratory passages (trachea) Elastic: numerous elastic fibers; found in external ear & larynx (vocal cords) (flexible) Fibrocartilage: many collagenous (tough); found b/w bones as shock absorber; b/w vertebrae & in knee

7) Bone Fxn: support, protection, framework Cells: osteocytes in lacunae; arranged in rings around canals Matrix: collagen w/ mineral salts (gives harding) Other: blood vessels found in canals, cellular processes connect to canals

8) Blood - Fluid Connective Tissue Fxn: transport, homeostasis Cells: red blood cells (erythrocytes), white blood cells (leukocytes), platelets (thrombocytes) Matrix: Plasma (contains blood cells & fragments of cells) Location: Blood vessels (arteries, veins, & capillaries)

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