Connective Tissue Proper Quiz

Connective Tissue Proper

• Connective tissue proper (CTP) is a type of connective tissue with a soft matrix.
• CTP is composed of three main components: fibers, cells, and matrix.

Fibers

• Collagen fibers:

  • Appear white in fresh state
  • Are strong and resist stretching
  • Form wavy bundles that branch
  • Can be boiled into gelatin
  • Digested by pepsin and collagenase
  • Stain acidophilic with H&E
  • Stain blue with Mallory trichrome stain
  • Stain red with Van Gieson’s stain
  • Classified into type I, II, and III collagen
    • Type I collagen is found in bone and white fibrocartilage.
    • Type II collagen is found in hyaline and yellow elastic fibrocartilage.
    • Type III collagen forms reticular fibers.

• Elastic fibers:

  • Appear yellow in fresh state
  • Are elastic
  • Are thin and long
  • Branch and may form elastic membranes, such as in the wall of the aorta
  • Resist boiling
  • Digested by elastase enzyme
  • Stain acidophilic with H&E
  • Stain yellow with Van Gieson’s stain
  • Stain black with Ver-Hoeff’s stain
  • Found in the walls of arteries, trachea, and ligaments between vertebrae.

• Reticular fibers:

  • Are very thin and form a network through branching and anastomosing
  • Stain black with silver
  • Not stained with H&E
  • Found in the stroma of organs such as the liver, spleen, and lymph nodes.

Matrix

• The matrix of CTP is composed of:
  • Organic components:
    • Amorphous component: Consists of proteins (collagen, elastin) and glycoproteins (proteins joined to carbohydrates).
    • Proteoglycans: Consists of proteins joined to disaccharides and are major components of the ground substance, including
      • Glycosaminoglycans (GAGs): Are polysaccharide chains with a high negative charge that attracts water, giving the ground substance its gel-like consistency.
  • Tissue fluid:
    • Consists of 60-70% water.

Cells

• Branched cells:

  • Undifferentiated mesenchymal cells (UMCs):
    • Are the mother cells of all CTP cells
    • Have a branched shape
    • Have an oval and large nucleus
    • Stain basophilic due to their abundant ribosomes
  • Fibroblasts:
    • Originate from UMCs, pericytes, and other fibroblasts.
    • Are numerous in loose CTP
    • Have a branched or spindle-shaped appearance
    • Have an oval, vesicular, and eccentric nucleus
    • Have basophilic cytoplasm with a negative Golgi image
    • Synthesize all types of CTP fibers and matrix
    • Contribute to the growth of CT and healing of wounds.
  • Macrophages:
    • Originate from blood monocytes
    • Have a large, branched shape with pseudopodia
    • Have an oval or kidney-shaped nucleus
    • Have unclear cytoplasm
    • Stain with vital stains such as trypan blue
    • Phagocytize foreign bodies such as bacteria and viruses
    • Secrete collagenase and elastase enzymes
    • May fuse to form multinucleated giant cells.
  • Pigment cells:
    • Contain melanin and are found in the skin and eye.

• Rounded or oval cells:

  • Fat (adipose) cells:
    • Unilocular fat cells:
      • Have an oval shape
      • Have a flat, peripheral nucleus
      • Have a large fat globule that pushes the nucleus to one side
      • Fat dissolves in H&E staining, leaving an empty space that looks like a signet ring
      • Stain orange with Sudan III
      • Stain black with Sudan black and osmic acid
      • Function in fat storage and heat insulation.
    • Multilocular fat cells:
      • Are smaller than unilocular fat cells
      • Have a rounded, central nucleus
      • Have numerous small fat droplets in their cytoplasm
      • Have numerous mitochondria
      • Function in heat production.
  • Mast cells:
    • Are found in the mucosa of the gastrointestinal and respiratory tracts
    • Have an oval shape
    • Have a rounded, central nucleus
    • Have large, basophilic granules in their cytoplasm
    • The granules consist of:
      • Sulphated glycosaminoglycans (heparin): an anticoagulant
      • Protein (histamine): a vasoactive substance
    • Stain purple with toluidine blue (metachromatic staining)
    • Secrete heparin and histamine during allergy.
  • Plasma cells:
    • Originate from B lymphocytes
    • Transition through a plasmablast stage
    • Are found in lymphatic organs
    • Have an oval shape
    • Have a rounded, eccentric nucleus with a "cartwheel" appearance.
    • Have deep basophilic cytoplasm with a negative Golgi image.
    • Secrete antibodies, contributing to humoral immunity.
  • Blood leucocytes (white blood cells):
    • Include eosinophils, neutrophils, monocytes, and lymphocytes, each with specific functions in the immune system.

Test your knowledge on connective tissue proper and its components, including collagen and elastic fibers. This quiz will cover the characteristics and classifications of these essential tissue elements. Perfect for students studying biology or anatomy.