Chapter 6 Tissues and Membranes

1. Chapter 6Tissues and Membranes

2. Introduction • Tissues are groups of cells similar to each other in structure and function. • Membranes are thin sheets of tissue that cover surfaces, line body cavities, and surround organs.

3. Types of Tissue • Epithelial Tissue Types • Epithelial tissue covers surfaces, lines cavities, and engages in secretion/absorption and protective functions. • Epithelial tissue is classified according to cell shape (squamous, cuboidal, and columnar) and layers (simple and stratified). • The types and functions are summarized in Table 6-1.

4. Types of Tissue - cont’d • Connective Tissue • The primary function of connective tissue is to bind together the parts of the body. Other functions include support, protection, fat storage, and transport of substances. • Connective tissue has an abundant intercellular matrix that fills spaces between cells. The intercellular matrix may be liquid, gel-like, or hard. The matrix often contains protein fibers that are secreted by the cells. • There are three types of loose connective tissue: areolar, adipose, and reticular.

5. Types of Tissue - cont’d • Connective Tissue—cont’d • Dense fibrous connective tissue forms tendons, ligaments, capsules, and fascia, and is found in the skin (dermis). • Types of cartilage include: hyaline, elastic, and fibrocartilage. • Bone (osseous tissue) is connective tissue formed by osteocytes. Bone cells have a hard intercellular matrix that includes collagen, calcium salts, and other minerals. • Blood and lymph are types of connective tissue that have a watery intercellular matrix.

6. Types of Tissue - cont’d • Nervous Tissue • Nervous tissue is found in the peripheral nerves, brain, and spinal cord. • The two types of nervous tissue are neurons, which transmit electrical signals, and neuroglia, which support and take care of the neurons. • Muscle Tissue • Muscle cells contract, thereby causing movement. • The three kinds of muscle are skeletal, smooth, and cardiac.

7. Tissue Repair • Tissue Repair by Regeneration • Replacement of tissue by cells that undergo mitosis • Tissue Repair by Fibrosis • Formation of scar tissue

8. Membranes • Epithelial Membranes • The cutaneous membrane is the skin. • Mucous membranes are epithelial membranes that line all body cavities that open to the exterior of the body. • Serous membranes are epithelial membranes that line the ventral body cavities, which are not open to the exterior of the body. • Serous membranes form two layers: a parietal layer that lines the wall of the cavity and a visceral layer that covers the outside of an organ. • The three serous membranes are the pleura, the pericardium, and the peritoneum.

9. Membranes - cont’d • Connective Tissue Membranes • Synovial membranes are connective tissue membranes. • Other connective tissue membranes are listed in Table 6-3.