Exam 1: Extracellular Matrix Flashcards
Ground substance
transparent, hydrated, fills space between cells and fibers
structure
Glycosaminoglycans (GAGs)
disaccharides
attract extracellular fluid - hydrating effect resists compression
Grave’s disease
increased deposition of GAGs in retro-orbital space
Proteoglycans
linear chain of glycosaminoglycans bound to protein core
Non-covalently linked to hyaluronic acid
Syndecan
Proteoglycan
transmembrane protein
in fibroblasts, serve as co-receptor for fibroblast growth factor
Perlecan
Proteoglycan
found in basement membranes and connective tissues
Cell adhesion, proliferation, development
promotes tumor proliferation and angiogenesis; inactivation results in defective skeletal development
Versican
Proteoglycan
cell to cell and cell to ECM interactions
Multiadhesive glycoprotein
thether cell to extracellular elements
three binding sites - one for integrin, collagen, and proteoglycan
Fibronectin
binds to integrins, collagen, heparin, hyaluronic acid
Located in connective tissue and blood
Laminin
Located in basal lamina
binds to integrins, heparan sulfate, collagen, entactin
Nidogen (Entactin)
In basal lamina
binds to laminin and collagen
Chondronectin
in cartilage
binds to collagen, chondroitin sulfates, integrins
Osteonectin
in bones
binds to collagen, proteoglycans, integrins of bone cells
Collagen
most abundant protein in body
made of glycine (every 3rd amino acid), hydroxyproline, and hydroxylysine
Type 1 Collagen
most abundant
in dermis, tendon, bone, fibrocartilage
Resistance to tension
fibril-forming collagen leading to formation of fibers
Type II collagen
hyaline and elastic cartilage
Resistance to pressure
fibril forming collagen
Type III collagen
in spleen, liver, lymph nodes, smooth muscle, skin, lung
Maintains structure in expansible organs
fibril forming collagen
Type IV collagen
found in basal lamina
support delicate structures and filtration
Type VII
in Dermis
anchors lamina densa to lamina reticularis
Reticular
fibers composed of collagen type III
react with silver and PAS
Elastic
imparts tissues with elasticity
slender branched fibers or fenestrated sheets
Ehlers-Danlos type IV
defect in type III collagen
cause varicose veins, aortic rupture, intestinal rupture
Ehlers-Danlos type VI
defective hydroxylation of lysine
Hyperelasticity of skin, rupture of eyeball
Ehlers-Danlos type VII
defect in type I collagen
joint dislcation and hypermobility of joints
Scurvy
decreased hydroxylation of proline caused by vitamin C deficiency
Gum ulceration and hemorrhages
Osteogenesis imperfecta
defect in type I collagen
Spontaneous fractures and cardiac insufficiency
Marfan syndrome
defective synthesis of elastic fibers,
aortic aneurysm , skeletal defects
Basal lamina
lamina lucida and lamina densa
Basement membrane
BL + lamina fibroreticularis
lamina lucida
laminin, entactin, integrins
Lamina densa
type IV collagen, fibronectin
Lamina fibroreticularis
fibronectin and types I and III collagen
