World Library  
Flag as Inappropriate
Email this Article

Perilymph

Article Id: WHEBN0002734348
Reproduction Date:

Title: Perilymph  
Author: World Heritage Encyclopedia
Language: English
Subject: Auditory system, Cochlea, Reissner's membrane, Tympanic duct, Reticular membrane
Collection: Body Fluids, Ear
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Perilymph

Perilymph
Cross-section of cochlea. Perilymph is located in the scala vestibuli and scala tympani - the aqua regions at the top and bottom of the diagram.
Cross-section of semi-circular canal and duct showing perilymphatic space
Details
Latin perilympha
Anatomical terminology

Perilymph (also known as Cotunnius' liquid, and liquor cotunnii) is an extracellular fluid located within the cochlea (part of the inner ear) in two of its three compartments: the scala tympani and scala vestibuli. The ionic composition of perilymph is comparable to that of plasma and cerebrospinal fluid. The major cation (positively charged ion) in perilymph is sodium: The values of sodium and potassium concentration in the perilymph are 138 mM and 6.9 mM, respectively.[1]

Contents

  • Structure 1
    • Composition 1.1
  • Clinical significance 2
  • References 3
  • External links 4

Structure

The inner ear has two parts: the bony labyrinth and the membranous labyrinth. The membranous labyrinth is contained within the bony labyrinth, and contains a fluid called endolymph. Between the outer wall of the membranous labyrinth and the wall of the bony labyrinth is the perilymphatic space which contains the perilymph. The membranous labyrinth is suspended in the perilymph. The perilymph in the bony labyrinth is continuous with the cerebrospinal fluid of the subarachnoid space via the perilymphatic duct.[2]

Composition

Perilymph and endolymph have unique ionic compositions suited to their functions in regulating electrochemical impulses of hair cells. The electric potential of endolymph is ~80-90 mV more positive than perilymph due to a higher concentration of potassium cations (K+) than sodium (Na+).[3]

Perilymph is the fluid contained within the bony labyrinth, surrounding and protecting the membranous labyrinth; perilymph resembles extracellular fluid in composition (sodium salts are the predominate positive electrolyte) and, via the perilymphatic duct, is in continuity with cerebrospinal fluid.

Endolymph is the fluid contained within the membranous labyrinth of the inner ear; endolymph resembles intracellular fluid in composition (potassium is the main cation).

Clinical significance

It has also been suggested that perilymph and endolymph participate in a unidirectional flow that is interrupted in Ménière's disease.

References

  1. ^ Bosher SK, Warren RL (1968-11-05). "Observations on the electrochemistry of the cochlear endolymph of the rat: a quantitative study of its electrical potential and ionic composition as determined by means of flame spectrophotometry".  
  2. ^ Blumenfeld, Hal (2010). Neuroanatomy through Clinical Cases second edition. Sinauer Associates, Inc. 
  3. ^ Konishi T, Hamrick PE, Walsh PJ (1978). "Ion transport in guinea pig cochlea. I. Potassium and sodium transport".  

External links

  • http://oto.wustl.edu/cochlea/intro3.htm
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.