Vertebrate Tissues 4 Basic Tissue Types B.Connective Tissue Supports, binds together, protects Most widely distributed tissue in body Usually well-vascularized Has a matrix - material between cells Consists of fibers and a ground substance 2 types of fibers Collagenous fibers - thick threads of protein (collagen); flexible; hold things together; white fibers Elastic fibers - made of protein called elastin; weaker than c.f. but stretch easily; vocal cords; yellow fibers (continued) 1. Loose connective tissue (Areolar Tissue) Cells are mainly fibroblasts (cells that produce fibers in the matrix) Matrix = gel-like ground substance and many collagen and elastin fibers Binds skin to organs & fills space btwn muscles Has many blood vessels that nourish nearby epithelial cells Loose Connective Tissue 2. Adipose Tissue (fat) Made up of cells that store fat Beneath skin; between muscles; around kidneys; surface of heart; around joints Cushions joints and organs Insulates Stores energy Adipose Tissue Large, empty-looking cells with thin margins; nucleus pressed against cell membrane 3. Dense Connective Tissue Densely packed, parallel collagen fibers (white) with only a few fibroblasts Very strong; makes up tendons and ligaments Low blood supply injuries slow to heal Dense Connective Tissue fibroblasts 4. Cartilage Cartilage cells = chondrocytes Chondrocytes occupy small chambers called lacunae a. Hyaline Cartilage Very fine collagen fibers in matrix looks like glass Found on ends of bones, soft part of nose, rings that support airway, fetal skeleton Hyaline Cartilage lacunae Chondrocyte b. Elastic Cartilage Chondrocyte Lacunae Web-like mesh of elastic fibers Provides flexible, elastic support External ear and parts of larynx c. Fibrocartilage very tough, contains many collagen fibers absorbs shock Found in meniscus of knee, intervertebral discs, etc. Fibrocartilage lacunae chondrocyte 5. Bone Hardness due to mineral salts and many collagen fibers in matrix Matrix deposited in layers called lamellae around tubes called Haversian canals Haversian canals contain blood vessels Bone (cont.) Bone cells are called osteocytes located in lacunae (chambers) spread out between lamellae support, attachment for muscles, mineral storage, protection (cranial &thoracic cavities), forms blood cells Found in skeleton Bone Haversian CanalOsteocytes in lacunae Bone Haversian canal Osteocyte 6. Blood Transports materials throughout body; helps maintain homeostasis Matrix is fluid (called plasma) Blood Leucocytes Erythrocytes Thrombocytes