World Library  
Flag as Inappropriate
Email this Article

Extracellular fluid

Article Id: WHEBN0000479385
Reproduction Date:

Title: Extracellular fluid  
Author: World Heritage Encyclopedia
Language: English
Subject: Fluid compartments, Cytosol, Pathophysiology of hypertension, Signal enhancement by extravascular water protons, Table of volume of distribution for drugs
Collection: Cell Biology
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Extracellular fluid

Extracellular fluid content in humans

Extracellular fluid (ECF) or extracellular fluid volume (ECFV) usually denotes all body fluid outside of the cells. The remainder is called intracellular fluid.

In some animals, including mammals, the extracellular fluid can be divided into two major subcompartments, interstitial fluid and blood plasma. The extracellular fluid also includes the transcellular fluid, which comprises about 2.5 percent of the ECF.

In humans, the normal glucose concentration of extracellular fluid that is regulated by homeostasis is approximately 5 mM/L, and the pH is tightly regulated by buffers around 7.4. The volume of ECF is typically 15 L, of which 12 L is interstitial fluid and 3 L is plasma. Interstitial fluid makes up 16% of human body weight, and blood plasma, 4%.

Contents

  • Function 1
  • Constituents 2
  • Description 3
  • Location 4
  • Subcompartments 5

Function

Extracellular fluid, in conjunction with intracellular fluid, helps control the movement of water and electrolytes throughout the body. In order to maintain osmotic balance, the extracellular compartments of a mammal's body must be able to excrete and absorb water to and from the environment. Inorganic ions must also be exchanged between ECF and the external environment to maintain homeostasis. These exchanges occur across specialized epithelial cells and through a filtration process in the kidneys. Extracellular fluid allows a solute balance between the outside and the inside of the cell, or to produce a gradient (which is commonly used to initiate diffusion, osmosis, facilitated diffusion, active transport, etc.). Blood flow delivers oxygen to arterioles, capillaries, and venules and clears waste products of metabolism. A second flow of fluid important to organ function is filtration of plasma across the microcirculation into the interstitial lymphatic compartment of the ECF. Multiple mechanisms regulate this flow and the distribution of ECF between the plasma volume and interstitial lymphatic fluid compartments.

Constituents

Sodium (Na+ = 136–145 mEq/L) Potassium (K+ = 3.5–5.5 mEq/L) Calcium (Ca2+ = 2.2–2.6 mEq/L)

Chloride (Cl = 99–109 mEq/L) Hydrogen Carbonate (HCO3 22–26 mM)

It is poorer in proteins, as compared to intracellular fluid.

  • Ionic Composition

Na+ 150 (mM)

K+ 5 (mM)

Cl 110 (mM)

Description

Extracellular fluid is the body fluid that is not contained in cells. It is often secreted by cells to provide a constant environment for cellular operation.

Location

Human ECF is found in blood, lymph, body cavities lined with serous (moisture-exuding) membranes, cavities and channels of the brain and spinal cord, and in muscle and other body tissues.

Subcompartments

  • Interstitial fluid – the extracellular fluid bathing most tissues, excluding the fluid within the
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.