Specialized Cells Extracellular protein fibers Ground substance=fluid Connective Tissue Specialized Cells Extracellular protein fibers Ground substance=fluid

Connective Tissues Characteristics Most diverse tissues of the body CT never exposed to the outside environment Abundant extracellular matrix Varying degrees of vascularity Contain sensory receptors

Connective Tissue Functions Support & Protection Transportation of Materials Storage of Energy Reserves Defense of the Body

Connective Tissue Major Cell Types Fibroblasts Fixed cell Most common cell Large, star-shaped cell Produce fibers & GS Macrophages Wandering cell Specialized for phagocytosis Important in defense Mast cells Small, mobile Found near blood vessels Release chemicals to begin chemical defense Fat cells Adipose cells Permanent

Connective Tissue Fibers Collagen fibers Thick, long, straight Unbranched Composed of collagen Great tensile strength Abundant in dense CT Hold structures together Tendons, ligaments Elastic fibers Bundles of microfibrils Embedded in elastin Fibers branch Elastic Vocal cords, air passages Reticular fibers Very thin collagenous fibers Highly branched Form supportive networks Least common

Reticular fibers Mast cell Elastic fibers Fixed macrophage Antibody producing cell Free macrophage Collagen fibers Blood in vessel Fibroblast Stem cell Adipocytes (fat cells) Ground substance White blood cell

Types of Connective Tissues CONNECTIVE TISSUE PROPER FLUID CONNECTIVE TISSUES SUPPORTING CONNECTIVE TISSUES LOOSE DENSE BLOOD LYMPH CARTILAGE BONE Fibers create loose, open framework Flows within cardiovascular system Flows within lymphatic system Fibers densely packed Solid, rubbery matrix Solid, crystalline matrix

Connective Tissue Proper Loose Areolar Tissue Mainly fibroblasts Fluid to gel-like matrix Collagen fibers Elastic fibers Highly vascular Bind skin to structures Beneath most epithelial Between muscles Adipose tissue Adipocytes Cushions Insulates Store fats Beneath skin Behind eyes Around kidneys and heart

Connective Tissue Proper Loose Reticular connective tissue Composed of complex reticular fibers network Supports framework Walls of liver, spleen, lymphatic organs

Connective Tissue Proper Dense Dense connective tissue Packed collagenous fibers Few fibroblasts Poor blood supply Dense Regular connective tissue Parallel collagen fibers Tightly packed fibers Tendons-attach muscle to bone Ligaments-attach bone to bone Dense Irregular connective tissue Interwoven meshwork with no pattern Forms organ capsules, covers bone & cartilage & gives strength to skin

Fluid Connective Tissue Blood Fluid matrix called plasma High # of red blood cells Small # of white blood cells Platelets-blood clotting Transports Defends Clotting Flows throughout body in blood vessels Heart Lymph Flows within the lymphatic system Contains white blood cells Defends Transports

Supporting Connective Tissue-Cartilage Rigid matrix Chondrocytes in lacunae Avascular Three types Hyaline Elastic Fibrocartilage Hyaline cartilage Most abundant Closely packed collagen fibers Ends of bones Nose, respiratory passages Embryonic skeleton Elastic cartilage Flexible Abundant elastic fibers External ear, larynx Fibrocartilage Very tough Many collagen fibers Shock absorber Intervertebral discs Pads of knee and pelvic girdle

Three Types of Cartilage Hyaline Cartilage Elastic Cartilage Fibrocartilage

Supporting Connective Tissue-Bone Solid matrix Supports Protects Forms blood cells Attachment for muscles Skeleton Osteocytes-bone cells