Connective Tissue Quiz (BMS Learning Outcomes)

Connective Tissue: Structure and Function

• Origin: Derived from mesenchyme, the middle layer of embryonic germ layers.

• Major Functions:

  • Support and Connection: Connects tissues and body parts, including supporting epithelium.
  • Strength: Provides tensile strength, crucial for resisting mechanical stress in ligaments and skin.
  • Protection and Repair: Houses immune cells, crucial for pathogen defense and wound healing.
  • Transport: Facilitates the transport of water, ions, and inorganic materials from blood to tissues.
  • Insulation and Storage: Adipose tissue insulates and stores energy (lipids), while the ground substance stores water, ions, and other materials.

Extracellular Matrix (ECM)

• Composition: A non-cellular component, primarily composed of proteins and polysaccharides structured as fibres embedded in an amorphous matrix.
• Function: Produced and organized by connective tissue cells for strength and specialized properties.
• Differentiation: Determines the final properties of the tissue based on specific components in the ECM, such as calcification to form bone or teeth.
• Examples: Specialized ECMs form tendons, cartilage, or the eye's cornea, while generalizations include loose or dense connective tissues based on the arrangement of fibres.

Connective Tissue Cells

• Adipocytes: Fat storage cells crucial for energy metabolism and body insulation.
• Chondrocytes: The primary cell type in cartilage, with a crucial role in support and flexibility.
• Fibroblasts: Found in dense connective tissue, characterized by collagen fibres and an organized arrangement.
• Reticular Cells: Located in reticular connective tissue, providing support to bone marrow, liver, and lymphoid tissues.

Connective Tissue Fibres

• Secretion: Secreted by fibroblasts, offering a supporting network for cell attachment.
• Types:
  • Elastic fibres: Composed of elastin, providing elasticity, allowing tissues to return to their original shape after stretching. (Can stretch up to 1.5 times original length). Microscopic appearance: Isolated, branching threads.
  • Collagen fibres: The most abundant type, primarily collagen, providing tensile strength (resistance to stretching). Arrangement: Thin and irregular in loose CT, providing support to vessels and nerves; Thick and tightly arranged in tissues needing high tensile strength.
  • Reticular fibres: Composed of randomly arranged collagen fibrils in a matrix; Form a fine meshwork (reticulin) to provide supporting scaffolding for soft tissues like the liver and bone marrow.

Connective Tissue Types and Subtypes

• Connective Tissue Proper:
  • Loose Connective Tissue: Widely distributed throughout the body.
    • Areolar: Found beneath skin's epidermis, lining mucous membranes and surrounding nerves/blood vessels. Crucial for support and protection; endomysium is a specific example of areolar tissue, covering individual muscle fibers.
    • Adipose: Stores fat, providing insulation, and cushioning organs.
      • White adipose: A primary component in those classified as obese; accounts for a significant portion of body fat.

Explore the vital roles of connective tissue in the body, including support, strength, protection, and transport. This quiz will assess your understanding of the origin, functions, and composition of connective tissue and the extracellular matrix (ECM). Test your knowledge on how these components contribute to overall bodily function.