Extracellular space

The extracellular space (EZR) (synonymous intercellular space , or intercellular space , medicinally also Latin : Spatium intercellulare ) is the space between the cell membranes within the tissue of multicellular living beings . It refers to the space outside the cells that is filled with tissue fluid and extracellular matrix . In addition to this, the space within the cell is called the intracellular space .

properties

The cell membrane (and in plants also the cell wall ) represents a barrier between two cellular spaces with very different chemical environments. B. Na ⁺ / K ⁺ - ATPase pumps for high sodium and low potassium levels outside the cells. This is u. a. necessary for the excitability of the cell.

The extracellular space itself is in turn divided into two compartments, the intravascular space (IVR, intravascular compartment; from Latin vas "vessel") located within the heart chambers, blood and lymph vessels and the extravascular space located outside of the vessels (EVR, extravascular compartment).

The extracellular space contains metabolites , ions , proteins and many other substances that influence cell function. So u. a. Neurotransmitters are transmitted from cell to cell via the EZR. Even hormones are transported via the ECR to the cell receptors. Other proteins that are active outside the cell are the digestive enzymes.

The term extracellular is also often used to refer to extracellular fluid (ECF), of which there are about 15 liters in the average human body. The transcellular fluid , which is also included in the extracellular space, is located in the pleural , peritoneal and pericardial cavities as well as in the cerebrospinal fluid , the eye chamber and the urinary and gastrointestinal tract .

The nature of the intercellular space has a major influence on the strength and flexibility of tissues, as well as the transport of water, nutrients and signals between cells.

• In animals , the intercellular space is filled with the extracellular matrix or intercellular substance and the tissue fluid . The intercellular spaces are smallest in epithelia with a width of about 25 µm and take up a large part of the tissue volume in connective tissue.

• In plants and fungi , the cell walls make up a large part of the intercellular space. If there are air-filled spaces between the cells, we speak of intercellular spaces . The totality of the non-cellular spaces within a plant is called the apoplast .

See also : third room

literature

• Schmidt, Lang (Ed.): Physiology of the people: With pathophysiology. Springer, Berlin; 30th edition 2007. ISBN 978-3540329084 .
• Klaus D. Mörike, Eberhard Betz, Walter Mergenthaler: Human biology. 15th edition. Nikol Verlag, Hamburg 2001, ISBN 3-937872-55-8 .
• Peter Sitte , Elmar Weiler , Joachim W. Kadereit , G. Neuhaus, Uwe Sonnewald : Textbook of botany for universities. 36th edition. Spectrum Akademischer Verlag, Heidelberg 2008, ISBN 978-3-8274-1455-7 .

Web links

• Electron microscope images of the intercellular space in human and rat tissues (Dr. Jastrow's EM Atlas)