G4 - Connective Tissue Flashcards
What are the various supportive functions of connective tissue?
- Stroma of glands and organs (like bookshelves for books)
- Medium for metabolic exchange
- Structural framework of the body
- Protection and defense
- Fat storage
ID the epithelium vs connective tissue borders. What type of epithelial tissue is shown here? What are the lighter colored cells in the epithelium?
Epithelium above red line and connective tissue below it
Pseudostratified columnar with goblet cells
What is extracellular matrix composed of?
Ground substance and fibers
What are the arrows in purple showing vs the arrows in blue?
Purple = ground substance
Blue = fibers
What are the arrows in purple showing vs the arrows in blue?
Purple = ground substance
Blue = fibers
This type of tissue has a lot of extracellular matrix and a small amount of cells.
Connective tissue
What does ground substance consist of?
Glycosaminoglycans (GAGs), proteoglycans, and non-collagenous glycoproteins (i.e. fibronectin)
What are glycosaminoglycans (GAGs) composed of?
hyaluronic acid and disaccharide polymers with sulfate groups
ID what the arrows are pointing at for each number.
- Collagen fibrils
- Hyaluronic acid molecule
- Proteoglycan aggregate
What is a proteoglycan aggregate composed of?
Hyaluronan which makes up the axis
Core proteins which attach to hyaluronan
GAGs attached to core proteins
What are the arrows pointing at? What is the center axis?
GAGs
Center axis = core protein
What does fibronectin do?
It binds proteins together and forms networks
What are the types of fibers found in connective tissue?
Collagen and elastic fibers
This type of fiber does not stain with H&E.
Elastic fiber
What are each of the arrows pointing at?
Top arrow = collagen
Bottom arrow = elastic fiber
What is the function of collagen?
To impart tensile strength
What is shown here in dark pink?
Collagen bundles
What is the arrow pointing at here?
Collagen fibers arranged as fibrils
List some clinical disorders that may result from defects in collagen synthesis.
Ehlers-Danlos syndrome
Scurvy
Osteogenesis imperfecta
Fibrosis
What is shown here in white?
Lung fibrosis
What is fibrosis?
Excessive scar tissue formation inside the body, aka excessive production of collagen
What are the major types of collagen and what do they make up?
Type I - skin, bone, tendon (90% of collagen in body)
Type II - cartilage
Type III - reticular fibers
Type IV - nonfibrilar, in basal lamina and binds to laminin, separates the epithelium from connective tissue
This type of collagen can only be visualized with silver stain.
Type III (reticular fibers)
What are the black and red arrows pointing at?
Black = hemidesmosomes
Red = basal lamina (type IV collagen)
What are the black arrows pointing at?
Reticular fibers (collagen type III)
What do reticular fibers/reticulin (collagen type III) do?
They form stroma (supporting network) around functional cells (parenchyma) of many organs
Reticular fibers are argyrophilic. What does this mean?
They stain with silver salts
What are the red arrows pointing at?
Reticular fibers (collagen type III)