4.1 - Lecture - CT Flashcards
Mesenchymal Stem Cell (MSC)
Gives rise to the cells that are responsible for generating connective tissue
Unilocular Adipocytes
- also known as white fat cells
- large cells that store lipids
- often occur together in large masses as adipose tissue
Multilocular Adipocytes
- lipid storing cells specialized for heat production
- occur primarily in neonates
Fibroblasts
- responsible for production, remodeling , degradation of the extracellular matrix fibers and ground substance
Myofibroblasts
- Myosin-producing subtype of fibroblasts
- specialized to generate force
Type I Collagen
- the dominant fiber of connective tissue
- synthesized as triple-helix procollagen molecules within fibroblast
- synthesized inside of fibroblasts
- extracellular are aligned + cross-linked into fibrils
Type III Collagen
- known as reticular fibers
- much smaller than collagen type I
- do not have a space-filling function
Elastic Fibers
- Composed of elastins and fibrillins
- found where stretchiness is required
Types IV and VII Collagen
- Found within basement membranes
- type IV is incorporated into/makes up a large portion of the lamina densa
- Type VII forms rings in the lamina reticularis to connect with other cytoskeletal elements
Type II Collagen
Crucial to the structure of cartilage
Type X Collagen
Found in the growth plate of bones
Ground Substance
= the space between connective tissue cells and fibers
- consists of highly hydrated complexes of glycosaminoglycans, proteoglycans, glycoproteins
- has extracellular long-chain proteins that keep ECM hydrated by binding water in lg. quantities
Glycosaminoglycans
- part of the highly hydrated complexes making up the ground substance
Proteoglycans
- have large sugar chains
- repeating units of the sugar chains
Glycoproteins
- have seen before as secretions (mucins) or intergral membrane proteins (contributing to a glycocalyx)
- also form component of ground substrates distinct from proteoglycansand fibers
- sugar chains are much smaller than those found in proteoglycans
Hyaluronic Acid
= a typical glycosaminoglycan “backbone molecule”
- organizes into numerous proteoglycan “core” molecules
- each subunit consists of numerosu glycosaminoglycan chains which attract water
Dermatan Sulfate
- a typical glycosaminoglycans
Heparan Sulfate
- a typical glycosaminoglycan
Keratan Sulfate
- a typical glycosaminoglycan
Chondroitin Sulfate
- a typical glycosaminoglycan
3 components of connective tissue proper
1) loose (aveolar)
2) Dense irregular
3) Dense regular
4 specialized connective tissue types
1) adipose tissue
2) blood
3) bone
4) cartilage
Loose (aveolar) CT (irregular) contains:
- Lots of ground substance (white space in lm)
- lots of cells
- very little fibers