title: The ultrastructure of the intra-articular disc of the temporomandibular joint, with special reference to fibrocartilage.
abstract: Cells in the intra-articular disc of the temporomandibular joint of the rat, guinea pig, rabbit, ferret, marmoset and sheep were studied at the ultrastructural level. The cells were generally rounded in outline and possessed moderate amounts of roughened endoplasmic reticulum and other organelles associated with protein synthesis and secretion. No intracellular collagen profiles were observed. Many of the cells possessed conspicuous amounts of microfilamentous material. Cell membranes in the rat, guinea pig, rabbit, ferret and sheep were closely applied to the collagen fibrils of the extracellular matrix. Occasionally in these animals, a narrow, irregular space containing microfilamentous material surrounded the cell membrane. Many cells in the marmoset differed from this description in being completely surrounded by an obvious pericellular matrix devoid of collagen fibrils and being comprised of microfilamentous material embedded in an amorphous ground substance. These chondrocyte-like cells in the intra-articular disc of the marmoset differed from chondrocytes in hyaline cartilage by lacking a pericellular capsule.
authors.affiliation: Division of Anatomy, Cell and Human Biology, GKT School of Biomedical Sciences, Strand Campus, Strand, London WC2R 2LS, England. Barry.Berkovitz@kcl.ac.uk
authors.forename: B K
authors.initials: BK
authors.lastname: Berkovitz
authors.forename: J
authors.initials: J
authors.lastname: Pacy
mesh_terms: D008841:Actin Cytoskeleton / Q000648:ultrastructure; D000818:Animals; D002144:Callithrix; D002358:Cartilage, Articular / Q000166:cytology / Q000648:ultrastructure*; D002452:Cell Count; D002462:Cell Membrane / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D019902:Chondrocytes / Q000166:cytology / Q000648:ultrastructure; D003094:Collagen / Q000648:ultrastructure; D003239:Connective Tissue Cells / Q000166:cytology / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D018870:Endoplasmic Reticulum, Rough / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000648:ultrastructure; D005289:Ferrets; D006168:Guinea Pigs; D006818:Hyalin / Q000648:ultrastructure; D008854:Microscopy, Electron; D015388:Organelles / Q000648:ultrastructure; D011817:Rabbits; D051381:Rats; D012756:Sheep; D013704:Temporomandibular Joint / Q000166:cytology / Q000648:ultrastructure*; D019224:Temporomandibular Joint Disc / Q000166:cytology / Q000648:ultrastructure*
chemical_list: D003094:Collagen