Common Characteristics of Connective Tissue Most common Well supplied with blood. (tendons and ligaments) Made up of many types of cells and extracellular matrix

Extracellular matrix Produced by the connective tissue cells then secreted to the exterior Can be liquid, gel-like, or solid Examples:  Fat tissue: mostly cells and a soft matrix  Bone: few cells and very hard matrix

Types of connective tissue 5 different types:  Bone  Cartilage  Dense connective tissue  Loose connective tissue  Blood

1. Bone Bone cells (osteocytes) sitting in cavities surrounded by a very hard ECM Protect and support other body organs

2. Cartilage Softer and more flexible than bone cells with a rubbery ECM Functions to absorb impact to the bone or form structures where elasticity is desired  Ex: the ear and between vertebrae, ribs

3. Dense Connective Tissue Contains fibroblast cells with tough fibers as the ECM Forms strong ropelike structures Tendons, ligaments, dermis

Tendons and Ligaments Tendons: attach skeletal muscles to bones  Less stretchy and contain less elastic fibers Ligaments: connect bones to bones at joints  More stretchy and contains more elastic fibers

4. Loose Connective Tissue Softer and have more cells and fewer fibers in ECM 2 main types:  Areolar  Adipose

Areolar Tissue Most widely distributed connective tissue Has several important functions 1. Universal packing tissue because it wraps around organs as protection 2. Hold organs in their proper positions

Adipose Tissue AKA fat Forms beneath the skin Protects the body from temperatures and provides some protection to organs

5. Blood Considered connective tissue because it is composed of blood cells surrounded by a fluid ECM called blood plasma Transport nutrients, wastes, and respiratory gases.