Chapter 4: Connective Tissue Flashcards
consists of different combinations of protein fibers (collagen and elastic fibers) and ground substance
extracellular matrix (ECM)
a tissue developing mainly from the middle layer of the embryo, mesoderm; where all connective tissues originate from
mesenchyme
undifferentiated cells with have large nuclei, with prominent nucleoi and fine chromatin
mesenchymal cells
Cells that produce and maintain most of the tissue’s extracellular components; synthesize and secrete collagen and elastin, GAGs, proteoglycans, and multiadhesive glycoproteins
Fibroblasts cells
Fibroblasts are targets of many families of proteins called _______, that influence cell growth and differentiation
Growth factors
Cells specialized for cytoplasmic storage of lipid as neutral fats, or less commonly for the production of heat
Adipocytes (fat cells)
Function in the localized release of many bioactive substances important in the local inflammatory response, innate immunity, and tissue repair
Mast cells
An anticoagulant, mast cell
Heparin
A mast cell that promotes increased vascular permeability and smooth muscle contraction
Histamine
Due to high content of acidic radicals in their sulfates GAGs, mast cell granules display ________ which means they change color of some basic dyes
Metachromasia
Components of connective tissue that are elongated structures formed from proteins that polymerize after secretion from fibroblasts
Fibers
Collagen, reticular, and elastic are all types of _____
Fibers
Collagen I, II, and III are all types of ________ ________
Fibrillar collagens
Have polypeptide subunits that aggregate to form large fibrils that are clearly visible in LM
Fibrillar collagens
Procured on polyribosome of the RER and traps located into the cisternae
Procollagen α chains
Remove the terminal globular peptides, converting procollagen molecules to collagen molecules
Procollagen peptidases
Mainly consist of collagen type III, which form an extensive network of thin fibers for the support of many different cells; common in immune system
Reticular fibers
Forms sparse networks interspersed with collagen bundles in many organs
elastic fibers
In the wall of large blood vessels, especially arteries, elastin also occurs as fenestrated sheets called _____
Elastic lamellae
The stains for defined elastic fibers and lamellae are _____ and _____
Orcein (weigerts) and aldehyde fuchsin
Elastic fibers are composite of _________, which forms a network of ________, embedded in a larger mass of cross-linked ______
Fibrillin; microfibrils; elastin
Four lysine residues in two elastin molecules condense to form ____
Desmosine ring
Highly hydrated, transparent, complex mixture of macromolecules: glycosaminoglycans (GAGs), proteoglycans, and multiadhesive glycoproteins
Ground substance
Long polymers do repeating disaccharide units, usually a hexosamine or uronic acid
GAGs (aka mucopolysaccharides)
Largest GAG; very long polymer of the disaccharide glucosamine-glucutonate
Hyaluronic acid/hyaluronate/hyaluronan
Synthesized in the cell membrane and is non-sulfated
Hyaluronic acid
Smaller, sulfated, bound to proteins (as part of proteoglycans), and are synthesized in the Golgi complexes
All other GAGs
Dermatan sulfate, chondroitin sulfates, keratan sulfate, and heparan sulfate are all _______
Four major GAGs found in proteoglycans
Consist of a core protein to which are covalently attached various sulfated GAGs
Proteoglycans
After secretion proteoglycans become bound to_______ polymers by _____ proteins and their GAG side chains associate further with _________ fibers and other ECM components
Hyaluronic acid; link; collagen
Key proteoglycans in all basal laminae
Perlecan
Vary large macromolecules with core protein heavily bound with chrondroitin and keratan sulfate chains; found in cartilage
Aggrecan
Have multiple binding sites for call surface integrins and other matrix macromolecules
Multiadhesive glycoproteins
A dimer with binding sites for collagens, certain GAGs, and integrins; important for cell adhesion and cellular migration
Fibronectin
Trimeric glycoprotein with binding sites for integrins, type IV collagen, and specific preteoglycans; providingg adhesion from epithelial and other cells
Laminin
Water in the ground substance of connective tissue; has an ion composition and plasma proteins of low molecular weight
Interstitial fluid
