hL5 - connective tissue

• list the components of connective tissues:

  • epithelium
  • basal lamina (basement membrane)

  connective tissue:

  • collagen fibres
  • macrophage
  • capillary
  • elastic fibres
  • fibroblast
  • mast cell
  • hyaluronan, proteoglycans, glycoproteins
• where do the connective tissues develop from?

  • mesoderm
• how do the connective tissues develop?

  • mesenchyme is undifferentiated connective tissue
  • have the potential to differentiate into further types of connective tissue
  • can happen in adults under certain circumstances (dental e.g., odontoblasts)
• what do the mesenchymal stem cells differentiate into?

  fibroblast - many connective tissues: skin, tendons, ligaments.

  osteocyte - bone

  chondrocyte - cartilage

  adipocyte - adipose (fat) tissues

  odontoblast - dentine
• what is the function of mast cells?

  allergen response
• what is the function of plasma cells?

  Produce antibodies

  synthesis of immunoglobulin
• what is the function of fat cells (adipose)?

  storage
• what is the function of lymphocytes?

  immune system
• what is the function of reticular cells?

  support
• what is the function of mesenchyme stem cells?

  Differentiation into various cell types.

  regeneration
• molecular components of connective tissues:

  collagen fibres:

  • consist of bundles of fibrils that are coils of collagen
  • help to strengthen connective tissue

  elastic fibres:

  • made of elastin and fibrillins - are stretchable
  • fibrillins are proteins found in oxytalan fibres in the periodontal ligament.
  • help give elasticity

  reticular fibres:

  • made of type-III collagen
  • form fine meshed networks around cells and cell groups
  • join connective tissues to other tissues

  ground substance

  hyaluronan

  glycosaminoglycan
• how would you classify loose connective tissue?

  few fibres

  many cells

  large amount of ground substance

  irregular network with spaces between the fibres

  holds organs in place

  attaches epithelial tissue to other underlying tissues.
• how would you classify dense connective tissue?

  smaller amount of ground substance

  lower number of cells

  more thick fibrous material

  helps attach muscle to bone

  link bones together at joints
• how would you classify specialized connective tissue?

  have different tissues with specialized cells

  unique ground substances

  some are solid and strong, some are fluid and flexible

  e.g., adipose, cartilage, bone, blood, lymph.
• pulp: soft connective tissue with collagen and reticular fibres
• periodontal ligament: 2 layers of dense connective tissue that surround the root of the tooth. collagen and reticular fibers in ground state.
• example of loose connective tissue:

  dental pulp:

  • contains cells of many types
  • contains fibres, not as many as it doesn't need strength.
  • all of these are set in a viscous semi-fluid matrix (ground substance)
• example of dense connective tissue:

  periodontal ligament:

  • contains cells of many types
  • many more fibres
  • more densely packed as it needs alot of strength
  • has a viscous matrix which acts as a shock absorber
• what happens when there's excessive synthesis and no degradation?

  gingival hyperplasia
• what happens when there's excessive degradation and no synthesis?

  periodontal disease