Connective Tissue Structure Connective tissue cells are farther apart than epithelial cell, with the space between cells filled with intercellular material called a matrix. Matrix consists of fibers and a ground substance that varies from fluid (blood plasma) to solid (bone). Function Connective tissue binds structures together, much like fasteners. Provide support by serving as a framework for attachment.

Fibroblast proteins stained with fluorescent dyes Connective Tissue Fibroblasts Fibroblasts are the most common type of cell in connective tissue. These star-shaped cells produce fibers by secreting proteins into the matrix of connective tissues. Connective Tissue Fibers Collagenous fibers These fibers are thick threads of the protein collagen. These fibers are grouped in long parallel bundles. These fibers have great tensile strength , giving them the ability to resist a pulling force. These fibers are important components in ligaments and tendons. Fibroblast proteins stained with fluorescent dyes

Vocal cords in the larynx contain many elastic fibers Connective Tissue Connective Tissue Fibers Elastic fibers These fibers are composed of a protein called elastin. Elastin forms thin branching fibers, resulting in complex networks. Elastic fibers are weaker than collagenous fibers, but they stretch easily, then regain their original shape, much like a rubber band. Elastic fibers are found in parts of the body which stretch, such as vocal cords. Vocal cords in the larynx contain many elastic fibers

Loose Connective Tissue Structure Cells are mainly fibroblasts, and are widely separated by matrix containing collagenous and elastic fibers secreted by the fibroblasts. Loose connective tissue forms thin membranes. Function and Location Binds skin to underlying tissue. Fills spaces between muscles. Lies beneath most layers of epithelium where blood vessels are located. Skin Stratified squamous Loose connective tissue

Dense Connective Tissue Many closely packed collagenous fibers with few cells (mostly fibroblasts). Few blood vessels, making repair slow. Function and location Very strong, can withstand pulling forces. Binds body parts together Ligaments (holds bone to joints). Tendon (holds muscle to bone). Tendon Low magnification 3. Protects eye

Adipose Tissue Structure Fat is a specialized form of connective tissue formed in cells which store fat in their cytoplasm. Function Provides a cushion around joints and some organs. It serves as insulation. Fat is the major site of energy storage. Location Beneath skin and loose connective tissue Around heart and kidney In abdominal membranes

Hyaline Cartilage Structure Hyaline cartilage is the most common form of cartilage. The chondrocytes are found in small chambers (lacunae) surrounded completely by matrix. The matrix is composed of very fine collagen fibers, giving it an almost glass-like surface. Function and Location Found at the ends of bone where it plays an important role in bone growth. Forms protective rings around air passages 3. Hyaline cartilage is also found in joint and the nose.

Elastic Cartilage Structure Elastic cartilage consists of chondrocytes surrounded by a matrix consisting of a dense network of elastic fibers. Function and location Due to the elastic fibers, this connective tissue is flexible and provides a framework for: External ears Parts of the larynx (voice box) Elastic cartilage in the ear (right) can be distinguished by the stain for elastin that brings out the dense bundles

Fibrocartilage Structure Fibrocartilage is very tough and contains bundles of thick clearly defined collagen fibers Function and Location Fibrocartilage acts as a shock absorber for structures subjected to pressure, such as the intervertebral discs (pads) found between the bones of the vertebrae. Fibrocartilage also cushions bones in the knees.

Bone Structure 1. Bone is rigid due to the deposits of calcium salts. 2. The bone matrix also contains a large amount of collage, which gives bone some flexibility. 3. Bone matrix is deposited in thin layers called lamellae. These form concentric circles around tubes called osteonic canals. 4. Bone cells (osteocytes) are located in lacunae (small chambers) which are evenly spaced between lamellae. 5. Each osteonic canal contains a blood vessel, so bone cells are close to nutrient supply, resulting in rapid repair of injury.

Blood Structure Blood is composed of formed elements (red blood cells, white blood cells, and platelets) suspended in a fluid matrix (blood plasma). Most blood is formed in red marrow of long bones. Function Blood transports substances and helps maintain a stable internal environment. Red blood cells carry oxygen and carbon dioxide. White blood cells fight infections Platelets are responsible for blood clotting. Blood cells