Connective tissue is the most abundant and widely distributed of the primary tissues, but its amount in particular organs varies. For example, skin consists primarily of connective tissue, while the brain contains very little. This chapter provides knowledge of connective tissue, indicate common characteristics of connective tissue, and list and describe its structural elements. | 4 Tissue: The Living Fabric: Part B Connective Tissue Most abundant and widely distributed tissue type Four classes Connective tissue proper Cartilage Bone tissue Blood Table Major Functions of Connective Tissue Binding and support Protection Insulation Transportation (blood) Characteristics of Connective Tissue Connective tissues have: Mesenchyme as their common tissue of origin Varying degrees of vascularity Cells separated by nonliving extracellular matrix (ground substance and fibers) Structural Elements of Connective Tissue Ground substance Medium through which solutes diffuse between blood capillaries and cells Components: Interstitial fluid Adhesion proteins (“glue”) Proteoglycans Protein core + large polysaccharides (chrondroitin sulfate and hyaluronic acid) Trap water in varying amounts, affecting the viscosity of the ground substance Structural Elements of Connective Tissue Three types of fibers Collagen (white fibers) Strongest and most abundant type Provides high tensile strength Elastic Networks of long, thin, elastin fibers that allow for stretch Reticular Short, fine, highly branched collagenous fibers Structural Elements of Connective Tissue Cells Mitotically active and secretory cells = “blasts” Mature cells = “cytes” Fibroblasts in connective tissue proper Chondroblasts and chondrocytes in cartilage Osteoblasts and osteocytes in bone Hematopoietic stem cells in bone marrow Fat cells, white blood cells, mast cells, and macrophages Figure Macrophage Fibroblast Lymphocyte Fat cell Mast cell Neutrophil Capillary Cell types Extracellular matrix Fibers • Collagen fiber • Elastic fiber • Reticular fiber Ground substance Connective Tissue: Embryonic Mesenchyme—embryonic connective tissue Gives rise to all other connective tissues Gel-like ground substance with fibers and star-shaped mesenchymal cells Overview of Connective Tissues For each of the following examples of connective tissue, note: Description Function Location Connective Tissue Proper | 4 Tissue: The Living Fabric: Part B Connective Tissue Most abundant and widely distributed tissue type Four classes Connective tissue proper Cartilage Bone tissue Blood Table Major Functions of Connective Tissue Binding and support Protection Insulation Transportation (blood) Characteristics of Connective Tissue Connective tissues have: Mesenchyme as their common tissue of origin Varying degrees of vascularity Cells separated by nonliving extracellular matrix (ground substance and fibers) Structural Elements of Connective Tissue Ground substance Medium through which solutes diffuse between blood capillaries and cells Components: Interstitial fluid Adhesion proteins (“glue”) Proteoglycans Protein core + large polysaccharides (chrondroitin sulfate and hyaluronic acid) Trap water in varying amounts, affecting the viscosity of the ground substance Structural Elements of Connective Tissue Three types of fibers Collagen (white fibers) Strongest and most abundant type Provides high .
