Overview
This lecture covers the structure, types, components, and functions of connective tissue, emphasizing key cell types, fibers, and tissue classifications.
Structure and Components of Connective Tissue
- Connective tissue is composed of cells and extracellular matrix (ECM).
- The ECM consists of ground substance and fibers (collagen, elastin, reticular).
- Connective tissue is vascularized and provides nutrients to surrounding cells.
- Cells in connective tissue are separated by the extracellular matrix.
Types of Connective Tissue
- Three main categories: connective tissue proper, supportive connective tissue, and fluid connective tissue.
- Supportive connective tissue includes hyaline cartilage, fibrocartilage, and elastic cartilage.
- Fluid connective tissue includes blood (in the cardiovascular system) and lymph (in the lymphatic system).
- Connective tissue proper includes areolar, adipose, reticular, dense regular, and dense irregular connective tissues.
Fiber Types and Functions
- Collagen fibers: strongest fibers, provide structural strength.
- Elastic fibers (elastin): provide elasticity.
- Reticular fibers: branching, spider web-like fibers that support internal organs.
Major Cell Types and Their Functions
- Fibroblasts: produce ECM fibers (collagen, elastin, reticular) and ground substance.
- Adipocytes: store energy as fat and provide cushioning and protection.
- White blood cells (leukocytes): provide immune defense.
- Red blood cells: transport oxygen and carbon dioxide in the blood.
- Plasma cells: produce antibodies for immune response.
- Lymphocytes, neutrophilic, eosinophilic, and basophilic leukocytes: participate in immunity and defense.
- Macrophages: white blood cells involved in immune defense.
Key Terms & Definitions
- Extracellular Matrix (ECM) — non-cellular component between connective tissue cells, made of ground substance and fibers.
- Collagen fibers — strongest structural fibers in connective tissue.
- Elastic fibers (Elastin) — fibers that allow tissues to stretch and return to shape.
- Reticular fibers — branching fibers supporting internal organs.
- Fibroblast — cell that produces connective tissue fibers and ground substance.
- Adipocyte — fat cell for energy storage and cushioning.
- Leukocyte — white blood cell involved in immune response.
- Plasma cell — white blood cell that produces antibodies.
- Macrophage — immune cell that engulfs pathogens and debris.
Action Items / Next Steps
- Review the three categories of connective tissue and their examples.
- Memorize key cell types and their functions in connective tissue.
- Study the structure and purpose of collagen, elastic, and reticular fibers.