This site is 100% ad supported. Please add an exception to adblock for this site.

Extracellular matrix

Terms

undefined, object
copy deck
What are the 4 basic tissue types?
Epithelium, Connective Tissue, Muscle, Nervous tissue
What is tissue?
Cells + Extracellular matrix
What comprises ground substance?
Carbohydrates, proteins, electrolytes, and water with a jelly-like consistency.
What are the functions of GS?
- Resists comprssion
- Permits diffusion of nutrients & waste
What fibers are found in GS?
- Collagen fibers - structure
- Elastic fibers - stretch
What are glycosaminoglycans (GAGs)?
- CARBOHYDRATE chains.
- Negatively charged to attract NA+, and H20
- Resists COMPRESSION
- Covalently linked to proteoglycans
- Usually SULFATED
What is the only non-sulfated GAG?
- Hyaluronic acid - LARGE
- Causes gel state
What are proteoglycans (PGs)?
- PROTEIN core covalently linked to GAGs
- Attach NONCOVALENTLY to HA: GEL STATE, limiting diffusion
- Bacteria secrete hyaluronidase to permit rapid spreading
What are glycoproteins (GPs)?
- Repsonsible for cells binding to ECM
- Bind to cell INTEGRINS, COLLAGEN fibers, and PGs to fasten everything
What is COLLAGEN?
- Main ECM protein; flex but strong
- Made from tropocollagen molecules (3 alpha chains in a triple helix)
How is collagen synthesized?
- Preprocollagen: alpha chains with ADDED propeptide sequences
- 3 of these form a helix together with frayed ends
- Transported out, then PROCOLLAGEN PEPTIDASE cleaves propeptides to form tropocollagen mlcls
- Tropocollagen spontaneously assemble
What is the function of propeptides?
- Prevents intracellular formation of collagen
What are elastic fibers?
- Provide elasticity
- Made of protein elastin
What is the BASEMENT MEMBRANE?
- Light microscopic term. Narrow acellular region b/w eptih and CT
What comprises the BASEMENT MEMBRANE?
- Basal lamina --> produced by epith. cells
- Reticular lamina --> produced by CT cells
What is the BASAL LAMINA?
Lamina lucida + lamina densa
What is the LAMINA LUCIDA
Made of GP laminin --> attaches lamina densa to epithelium, INTEGRINS
What is the LAMINA DENSA?
Type IV COLLAGEN and PG
What is fibronectin?
GP in lamina densa that binds to reticular lamina

Deck Info

19

permalink