Connective Tissue

• Connective tissue:

  • Most diverse, abundant, widely distributed, structurally varied of the 4 main tissue types
  • “give” of body
  • includes blood, tendons, ligaments, fat, bones, cartilage
• Characteristics of connective tissue

  1). Cells

  2). Protein fibers

  3). Ground substance
• Cells

  • Different cells in different types of connective tissue
  • Ex. fibroblasts, osteocytes, adipocytes
• Protein fibers

  • elastic fibers, collagen, reticular fibers
• Ground substance

  • mixture of proteins/carbohydrates with variable amounts of salts and water
  • protein fibers and ground substance are composed of the extracellular matrix
• Then function of connective tissues are to protect, support, binds other tissues together.
• Connective tissue proper - cells

  • Fibroblasts
  • large, flat cells with tapered ends
  • Adipocytes
  • fat cells with white space in middle (white middle part = lipids, lipids don’t stain)
  • store lipid reserves
• Connective tissue proper - Protein fibers

  • collagen fibers
  • strongest/longest fiber
  • Elastic fibers
  • wavy
  • thinner than collagen
  • Reticular fibers
  • criss-crossing, woven framework
  • found in stroma of organs
• Connective tissue proper - ground substance

  • Combination of proteins and carbohydrates
  • Texture is gelatinous, semi-fluid (adipose), little sticky
• Connective tissue proper - Further classification

  1). Loose connective tissue: serves as body’s packing material, found in spaces around organs

  • ex. areolar, adipose, reticular

  2). Dense connective tissue: strong, has fibers (mostly collagen) packed tightly together

  • ex. dense regular, dense irregular, elastic
• What are the characteristics of connective tissue?

  Cells, protein fibers, ground substance
• What are the types of dense connective tissue?

  Dense regular, dense irregular, elastic
• What is collagen fibers known for?

  Strongest/largest fiber, most abundant
• Areolar connective tissue

  • abundant ground substance
  • scattered fibroblasts
  • surrounds/protects

  ex. papillary layer of dermis
• Where is areolar connective tissue found?

  papillary layer of dermis
• Adipose connective tissue

  • tightly packed adipocytes
  • stores energy, cushions organs, insulates

  ex. subcutaneous fat
• Reticular connective tissue

  • scattered fibroblasts, reticular fibers
  • provides supportive framework
• Dense regular connective tissue

  • densely packed parallel collagen fibers
  • resists stress in one direction

  ex. tendons
• Dense irregular connective tissue

  • randomly arranged collagen fibers
  • resist stress in all directions

  ex. dermis
• Elastic connective tissue

  • Many branching elastic fibers, fibroblasts
  • allowing stretching

  ex. walls of large, elastic arteries
• What is an example of elastic connective tissue?


  walls of large arteries