Chapter 4.2 Human Anatomy & Physiology Connective Tissue Chapter 4.2 Human Anatomy & Physiology

Connective Tissue Function: - Binds structures together - Provides support & protection - Fills spaces - Produces blood cells - Stores fat For energy, insulation, organ protection

Structure: - Tissue cells are widely separated by extracellular matrix - Can be solid, semisolid, or liquid Matrix of connective tissue determine its properties

Fibers of the Matrix White fibers – contain collagen which gives the fibers flexibility and strength Yellow fibers – contain elastin more elastic than collagen but not as strong Reticular fibers – thin, highly branched collagenous fibers that provide support

1. Fibrous Connective Tissue Loose (areolar) connective tissue adipose Dense connective tissue Regular irregular Reticular connective tissue

A. Loose (areolar) Connective Tissue Lies between other tissues or between organs binding them Cells made of fibroblasts – large, star-shaped cells Contains many white fibers (strong and flexible) and yellow fibers (very elastic)

Adipose tissue is a type of loose connective tissue - stores fats, provides insulation - found beneath skin, around kidney & heart, breast

B. Dense Connective Tissue Regular Consists of parallel bundles of collagenous fibers Found in tendons & ligaments Binds organs together Irregular Bundles run in different direction Found in inner portion of skin

Dense Irregular Dense Regular

C. Reticular Connective Has reticular cells and reticular fibers Also called lymphatic tissue Found in lymph nodes, spleen, thymus, and red bone marrow Store and produce white blood cells Part of immune system

2. Cartilage The cell (chondrocytes) lies in small chambers called lacunae Matrix is solid yet flexible Lacks direct blood supply, as a result, it heals slowly

3 types - Hyaline cartilage - Elastic cartilage - Fibrocartilage

A. Hyaline Cartilage Most common Matrix contains fine collagenous fibers Glassy, white, opaque Found in the nose, ends of the long bones and ribs, rings in the trachea

B. Elastic Cartilage Contains elastic and collagenous fibers Found in the outer ear

C. Fibrocartilage Matrix contains strong collagenous fibers Function: absorbs shocks and reduces friction between joints Found in the pads between the vertebrae and knee joints

3. Bones Most rigid of the connective tissues Minerals and protein fibers gives bone rigidity, elasticity and strength Two types: Compact bone Spongy bone

A. Compact Bone Found in the outer portion of long bones Consists of many cylindrical-shaped units called osteon

B. Spongy Bone Found on ends of long bone Contains bony bars and plates called trabeculae separated by irregular spaces Blood cells are made within the red marrow found in the spongy bone

4. Blood Connective tissue composed of cells suspended in liquid matrix called plasma Red blood cells (erythrocytes) – carries oxygen White blood cells (leukocytes) – fights infection Platelets – fragment of giant cells found in bone marrow