{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,28]],"date-time":"2025-10-28T10:43:55Z","timestamp":1761648235420},"reference-count":0,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[1984,4,7]],"date-time":"1984-04-07T00:00:00Z","timestamp":450144000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Exp Physiol"],"published-print":{"date-parts":[[1984,4,7]]},"abstract":"<jats:p>Recent morphometric studies of synovium lining the rabbit knee showed that capillaries extend to \u3009 200 \u00b5m below the synovial surface; that a proportion of the superficial capillaries are fenestrated; and that the numerical density of the capillaries varies with depth (Knight &amp; Levick, 1983, 1984). Such observations raised the question \u2018Down to what depth do capillaries contribute significantly to the diffusional flux of a small extracellular solute (e.g. sulphate) into the joint cavity?\u2019 This problem was addressed by a mathematical model of trans\u2010synovial diffusion. The periarticular tissue was considered as a stack of thin slices (\u0394<jats:italic>x<\/jats:italic> = 2\u20135 \u00b5m), each of known depth and capillary population. An expression for interstitial concentration normal to the surface was derived from the Fick diffusion equations and the mass\u2010balance equation for each slice. Morphometric values were substituted into the area and distance terms of the Fick equation. A range of values was explored for two permeability terms, namely <jats:italic>D<\/jats:italic><jats:sub>t<\/jats:sub>\/<jats:italic>D<\/jats:italic><jats:sub>i<\/jats:sub> (diffusivity across unit fenestral matrix relative to that across unit interstitial matrix) and <jats:italic>PS\/Q<\/jats:italic> (permeability\u2010surface area product\/blood flow for synovial fenestrated capillaries); the ranges lay between the estimated extreme values. Steady\u2010state concentrations and transcapillary fluxes at each depth were obtained by iterative calculation on a microcomputer. The thickness of tissue from which 80% of the joint influx arose (<jats:italic>T<\/jats:italic><jats:sub>0\u00b78<\/jats:sub>) was 7\u201313 \u00b5m for diffusion\u2010limited transcapillary exchange (<jats:italic>PS\/Q<\/jats:italic> = 0\u00b705; <jats:italic>D<\/jats:italic><jats:sub>t<\/jats:sub>\/<jats:italic>D<\/jats:italic><jats:sub>i<\/jats:sub> = 1\u20130\u00b703); or 9\u201317, \u00b5m for flow\u2010limited exchange (<jats:italic>PS\/Q<\/jats:italic> = 5; <jats:italic>D<\/jats:italic><jats:sub>t<\/jats:sub>\/<jats:italic>D<\/jats:italic><jats:sub>i<\/jats:sub> = 1\u20130\u00b703) in areolar synovium, which is the most extensive tissue. The relative independence of the results from the permeability conditions was due to the dominant effect of a peak in capillary density just below the synovial surface. The resistance of the capillary endothelial wall as a fraction of total blood\u2010joint barrier resistance was calculated to be 0\u00b718\u20100\u00b780 in areolar synovium under conditions of diffusion\u2010limited exchange.<\/jats:p>","DOI":"10.1113\/expphysiol.1984.sp002806","type":"journal-article","created":{"date-parts":[[2014,12,16]],"date-time":"2014-12-16T16:52:29Z","timestamp":1418748749000},"page":"289-300","source":"Crossref","is-referenced-by-count":5,"title":["AN ANALYSIS OF THE EFFECT OF SYNOVIAL CAPILLARY DISTRIBUTION UPON TRANS\u2010SYNOVIAL CONCENTRATION PROFILES AND EXCHANGE"],"prefix":"10.1113","volume":"69","author":[{"given":"J. R.","family":"Levick","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1984,4,7]]},"container-title":["Quarterly Journal of Experimental Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fexpphysiol.1984.sp002806","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/expphysiol.1984.sp002806","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,20]],"date-time":"2023-10-20T09:24:44Z","timestamp":1697793884000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/expphysiol.1984.sp002806"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,4,7]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1984,4,7]]}},"alternative-id":["10.1113\/expphysiol.1984.sp002806"],"URL":"https:\/\/doi.org\/10.1113\/expphysiol.1984.sp002806","archive":["Portico"],"relation":{},"ISSN":["0144-8757"],"issn-type":[{"value":"0144-8757","type":"print"}],"subject":[],"published":{"date-parts":[[1984,4,7]]}}}