Synol fluid - all are true except :
Secreted by Type A cells [Ref: Turek's Ohopaedics 6/e, p 152; Gray's 40/e, p 100; Biofluid Mechanics by Jagannath Mazumdar 2004; p 79-83. Type A synol cells are macrophage-like cells. They synthesize and release lyric enzymes and phagocytose joint debris. These cells are not considered to secrete synol fluid. Synol fluid: Is a plasma transudate from synol capillaires + hyaluronic acid- protein complex (mucin) secreted by Type B synol cells + cells (60-100 cells/ml; mainly lymphocytes and monocytes) The viscous and lubricating propey of the synol fluid is attributed to hyaluronic acid. Synol membrane has two types of cells? Type A cells Type B Cells * Less in number * Predominant cells * Macrophage like * Fibroblast like * Synthesize & release lytic * Synthesize & secrete hyaluronic acid enzymes & glycoproteins of synol fluid * Phagocytose joint debris * Have abundant rough ER * Have a prominent Golgi apparatus and little rough ER Synol fluid is a Non-newtonian, thixotropic fluid A Newtonian fluid is one which follows the Newtonian (friction) law i.e. its viscosity remains constant with agitation or varying shear rate (viscosity is only affected by temperature changes). Examples of Newtonian fluid are: water, oils, gases, mercury, alcohol etc. A Non-Newtonian fluid is one that does not follow the Newtonian (friction) law. Its viscosity changes with agitation or varying shear rate. A Non-Newtonian fluid can be Thixotropic or Rheopectic. Thixotropic is one whose viscosity decreases with agitation or varying shear rate. (Thus thixotropic fluid are thick (viscous) under normal conditions, but become thin, less viscous over time when shaken, agitated, or otherwise stressed.) Eg. Synol fluid, ketchup. Rheopectic is one whose viscosity increases with agitation or varying shear rate. Eg. gypsum pastes, printers inks, and some lubricants. Synol fluid has thixotropic propeies. Its viscosity decreases with increase in the rate of movement, thus it is able to provide better lubrication to the joints.
Secreted by Type A cells
Follows non newtonian fluid kinetics
Contains hyaluronic acid
Viscosity is variable