Human Endolymphatic Duct: An Ultrastructural Study

Abstract

\s=b\The fine structure of the human endolymphatic duct was observed by transmission electron microscopy. Wel l \x=req-\ preserved specimens were obtained after fixation of inner ear tissue by perilymphatic perfusion. The morphologic findings seemed to be in accordance with earlier propositions that the human endolymphatic duct may be involved in endolymph resorption. The duct was found to contain otoconialike bodies, suggesting that the endolymphatic duct and sac in man may also play a role in the turnover of macular otoconia. (Arch Otolaryngol 1984;110:421-428) The inner ear is anatomically di¬ vided into several compartments. Of these, three major functional units may be distinguished, namely, the cochlear labyrinth, which is the endorgan for hearing, the vestibular laby¬ rinth, which is the end-organ for the sense of equilibrium, and the endo¬ lymphatic duct and sac. The first two systems have been extensively studied

A Micro-CT and Synchrotron Imaging Study of the Human Endolymphatic Duct with Special Reference to Endolymph Outflow and Meniere’s Disease

“…They demonstrated an interconnecting system of peri-endolymphatic channels extending from the opening of the VA to the proximal ES and speculated about their hydrodynamic implications. These findings supported earlier observations of a looping system of periaqueductal bone channels, with vessels running in both horizontal and vertical directions and connected to thin periductal vessels 40 . An anastomotic network of thin capillary vessels was observed close to the epithelium of the ED, with vascular tributaries via periaqueductal bony channels.…”

“…Linthicum et al 29 also presented histopathological evidence of an osseous obstruction of the ED in a case of MD. SR-PCI findings support these results 29,39,40 and add new information as to the origin and organisation of the plexus containing a distal collecting system. In the present study, collecting ducts were located at the distal ED with the VVA.…”

Does severe water deprivation affect the inner ear?

“…Moreover, an increased concentration of an organic matrix located subepithelially was also observed. Similar findings were previously described by Friberg et al (1986) in the human ED, with the assumption that they were important for the proposed absorptive function taking place in this organ.…”

“Reversed polarization” of Na/K-ATPase—a sign of inverted transport in the human endolymphatic sac: a super-resolution structured illumination microscopy (SR-SIM) study

“…Experimental studies provide little evidence of an endolymph "flow" (Salt and DeMott 1997), a situation possibly altered under stress and various physiological demands (Rask- Andersen et al 1999). A trans-cellular transport of ions is consistent with observations of increased tight junction barriers in the distal ES as demonstrated by freeze fracturing, tracer studies, and morphological observations (Rask-Andersen et al 1981;Friberg et al 1984b;Hultgård-Ekwall et al 2003. Active cellular pumps in the intraosseous ES could induce a longitudinal "syphon" of endolymph (Møller et al 2013).…”