atrophy

from Wikipedia, the free encyclopedia

The atrophy or atrophia (too ancient Greek : ἀτροφία , modern Greek : ατροφία , neo-Latin : atrophia "emaciation", " wasting ", " lack of food", "stunted") describes as atrophy a reduction in size of a tissue, an organ or a single cell a reduction in function is associated. In contrast to congenital hypoplasia (reduced structure of an organ), atrophy is acquired.

Forms of atrophy

Basic forms of atrophy: A: normal state. B : Volumetric atrophy. C : Numerical atrophy. D Volumetric and numerical atrophy.

Atrophy can result from a decrease in the volume or size of the cells ( simple or volumetric atrophy ; hypotrophy ) or a decrease in the number of cells ( numerical atrophy ; hypoplasia ). The opposite of atrophy is hypertrophy or hyperplasia .

Atrophy can be natural (physiological) or diseased (pathological). Physiological forms of atrophy are:

  • Age atrophy : With age, all functional ( parenchymatous ) cells decrease in volume, which can be very pronounced, especially in the brain and heart. If lipofuscin is also present , one speaks of brown atrophy because of the brownish color of the organs.
  • Involutional atrophy : Certain organs are no longer needed or are no longer needed as much in certain phases of life and therefore regress. The thymus, for example, regresses almost completely in adults.

On the other hand, we know different forms of pathology due to pathological processes:

  • Inactivity atrophy : It occurs when an organ is not used, for example with a leg in a cast.
  • trophoneurotic / nerve atrophy : When a nerve is damaged, the muscle that it (no longer) supplies atrophies.
  • Vascular atrophy: If the blood vessels do not get enough oxygen and nutrients to the cells, they can atrophy. The condition is that this inadequate supply develops slowly (for example, a kidney artery that narrows over months). In contrast, cells die in the event of a sudden supply problem (e.g. heart attack ).
  • Pressure atrophy: If, for example, tumors press against the surrounding tissue, neighboring cells can atrophy and make room for the growing tumor.
  • Due to a lack of food: Generalized atrophy occurs, especially of the fatty tissue and muscles. Causes can be malnutrition, a disorder of absorption or a consuming disease (tumor, etc.). In the case of malnutrition, the disease is called marasmus , in the case of consuming disease, cachexia .
  • Endocrine atrophy: Atrophy occurs because of endokine signals, for example in cortisone therapy.

If the receding tissue is replaced by fatty tissue, it is called vacat fat overgrowth . This occurs particularly in the adult thymus.

See also

literature

  • Helmut Lingen (Ed.): Medicine, humans, health - diseases, causes, treatments from A – Z / Medical terms / The human body / Natural healing methods / First aid . Lingen, Cologne 2006.
  • Johannes Sobotta, Ulrich Welsch: Textbook histology. Cytology, histology, microscopic anatomy . 2nd Edition. Elsevier, Urban and Fischer, Munich 2006, ISBN 3-437-42421-1 .

Web links

Wiktionary: Atrophy  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ a b c d e f Matthias Krams et al .: Short textbook pathology , 2nd edition. Georg Thieme Verlag, Stuttgart 2013, ISBN 978-3-13-143252-0 , p. 25
  2. ↑ a b Ursus-Nikolaus Riede and Martin Werner (eds.): General and Special Pathology , 2nd edition. Springer Verlag, Berlin - Heidelberg, 2017, ISBN 978-3-662-48725-9 , p. 68.
  3. ↑ a b c d atrophy , accessed October 23, 2017