Chapter 3: Connective Tissue Proper

• Proper Connective Tissue

  – general about connective tissue
• SPECIALIZED

  = Cartilage Connective Tissue

  = Bone Connective Tissue

  = Blood Connective Tissue
• CONNECTIVE TISSUES

  • Most diverse group of tissue

  • Supports and binds tissues for all organs

  = Blood is considered connective tissues even though it is liquid
• ORIGIN OF CONNECTIVE TISSUES

  = Mesenchyme

  = Mesenchymal cells
• Mesenchyme 


  = Loose fluid type of embryonic tissues

  = Common origin of all connective tissues
• Mesenchymal cells


  = Can be situated in any way and can move from place to place
• Mesenchymal cells – small spindle shaped cells with large nuclei (multipotent stem cells) 


  = It can be differentiate as a progenitor cells

  = Unlike the Epithelial cells which have fixed neatly arranged in sheets
• CHARACTERISTICS

  = Different degrees of vascularity (blood flow)

  = It cells are separated by a large amount of intercellular space

  = Cartilage – avascular (there is no blood supply)

  = Dense irregular tissue in skin – vascular (there is a blood flow)

  Vascular = There is a presence of capillaries, veins and arteries
• COMPONENTS

  Extracellular Matrix (transparent and colorless)

  = Non-living components of connective tissues

  = Inert matrix (it locked the ability to move)

  1. Ground Substance

  2. Fibers
• GROUND SUBSTANCE

  = Watery, rubbery, unstructured material that fills the spaces between cells (it is highly hydrated, plenty of water are bounded)

  = Protects the cells in the extracellular matrix

  = Flexible - made of starch, protein molecules and water

  = Proteoglycans – anchors this framework

  = GAG or Glycosaminoglycans – sprouts from proteoglycans
• THREE (3) MAJOR KINDS OF MACROMOLECULES

  = Glycosaminoglycans (GAGs) – Mucopolysaccharides

  = Proteoglycans

  = Multi-adhesive glycoproteins
• Glycosaminoglycans (GAGs) – Mucopolysaccharides

  = Hyaluronan – largest, most ubiquitous

  • Molecular diffusion

  • Lubrication
• Proteoglycans


  Perlecan – basal laminae (the key proteoglycan in all basal lamina)

  Aggrecan – articular cartilage (the most abundant and the most important proteoglycan in articular cartilage)
• Multi-adhesive glycoproteins

  = Binding site for cell surface integrins and macromolecules
• FIBERS

  Provide support and structure to the otherwise shapeless ground substance
• FIBERS

  = Collagen

  = Elastic Fibers

  = Reticular Fibers
• Collagen


  = strongest and most abundant type, tough and flexible

  = The most abundant protein
• Elastic Fibers – 


  = longer and thinner which form a branching framework within the matrix

  = Made of protein elastin – allows them to stretch and recoil

  = Found in the skin, lungs and blood vessels walls
• Reticular Fibers

  = Short, finer collagen fibers with an extra coating of glycoprotein

  = Forms a delicate, sponge-like networks that cradle and support the organs
• COLLAGEN FIBERS

  = Strongest and most abundant type of fiber

  = Appears neat and smooth “white, flexible” structures under the microscope

  = Provide great resistance to tension
• ELASTIC FIBERS

  = Form a branching framework

  = Stretch and recoil like rubber bands
• RETICULAR FIBERS

  = Short, finer collagen fibers

  = Sponge like networks
• CELLS

  = Blast

  = Chondroblast

  = Osteoblast

  = Osteoblast
• Blast 


  = Literally means “forming”

  = Stem cells or immature cells

  = Undergoes mitosis to replicate themselves

  = Has different types with different functions

  = Once they mature they transition from -blast to - cyte’ (b before c)
• Chondroblast

  = Blast cells of cartilage
• Osteoblast 


  = blast cells of the bone tissue
• Macrophages

  = provide immune defense for connective tissues, phagocytize bacteria, foreign materials and dead cells
• CONNECTIVE TISSUE PROPER

  = LOOSE (LARA) Areolar Reticular Adipose

  = DENSE (DRIE) Regular Irregular Elastic
• CONNECTIVE TISSUE PROPER

  = Most diverse group in the tissue family.
• Loose Connective Tissue

  = Areolar

  = Reticular

  = Adipose
• Dense Connective Tissue

  = 1 Regular

  = 2 Irregular

  = 3 Elastic
• LOOSE CONNECTIVE TISSUE

  = Have fewer fibers, and more cells and more ground substance
• 1. Mesenchyme – embryo, fetus
  2. Mucoid – Wharton’s jelly or umbilical cord
  3. Adipose – subcutaneous tissue (dermis)
  4. Reticular – bone marrow, lymph node, spleen
• DENSE CONNECTIVE TISSUE

  Regular - tendon, stroma of cornea

  Irregular – dermis, capsules of organs
• Tendon

  • Dense connective tissue
  • Connect your bone to muscle and muscle to muscle
• Ligament

  = Dense connective tissue

  = Connects your bone to bone
• Areolar Connective Tissue

  = Most common loose connective tissue

  = Found all over the body

  = Under the epithelial tissue and wrapped around the organs

  A)

  B)

  C)
• Areolar Connective Tissue

  A)

  B)

  
• Adipose Connective Tissue

  = Fat tissue

  = Is not mostly ground substance

  = Is mostly cells

  – adipocytes

  – which stores lipids for later use
• Adipose Connective Tissue

  Adipocytes

  Nucleus

  Lipid Vacuole

  A) Adipocytes

  B) Nucleus

  C) Lipid Vacuole