SECTION 4-3 Connective Tissues

Connective tissue functions: Establishing a structural framework Transporting fluids and dissolved materials Protecting delicate organs Supporting, surrounding and interconnecting tissues Storing energy reserves Defending the body from microorganisms

Figure 4.8 A Classification of Connective Tissues

Connective tissues contain Specialized cells Matrix Composed of extracellular protein fibers and a ground substance

Connective tissue proper Contains varied cell populations Contains various fiber types A syrupy ground substance

Fluid connective tissue Contains a distinctive cell population Watery ground substance with dissolved proteins Two types Blood Lymph

Supporting connective tissues Less diverse cell population Dense ground substance Closely packed fibers Two types Cartilage Bone

Connective tissue proper Contains fibers, a viscous ground substance, and a varied cell population Fibroblasts Macrophage Adipocytes Mesenchymal cells Melanocytes Mast cells Lymphocytes Microphages

Connective tissue proper Three types of fiber Collagen fibers Reticular fibers Elastic fibers

Connective tissue proper Classified as loose or dense Loose Embryonic mesenchyme, mucous connective tissues Areolar tissue Adipose tissue Reticular tissue Dense Dense regular CT Dense irregular CT

Figure 4.9 The Cells and Fibers of Connective Tissue Proper

Figure 4.10 Connective Tissue in Embryos

Figure 4.11 Adipose and Reticular Tissues

Figure 4.12 Dense Connective Tissues Figure 4.12a

Figure 4.12 Dense Connective Tissues Figure 4.12b

Figure 4.12 Dense Connective Tissues Figure 4.12c

The Tissue Level of Organization Chapter 4, part 3 The Tissue Level of Organization

Fluid connective tissues Distinctive collections of cells in a fluid matrix Blood Formed elements and plasma Red blood cells, white blood cells and platelets Arteries carry blood away, veins carry to the heart Capillaries allow diffusion into the interstitial fluid Lymph Interstitial fluid entering the lymphatic vessels

Figure 4.13 Formed Elements of the Blood

Supporting connective tissues—a look ahead… Cartilage and bone support the rest of the body Cartilage Grows via interstitial and appositional growth Matrix is a firm gel containing chondroitin sulfate Cells called chondrocytes Cells found in lacunae Perichondrium separates cartilage from surrounding tissues Three types: hyaline, elastic and fibrocartilage