Ganglion (nervous system)

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A ganglion ( plural ganglia ) is an accumulation of nerve cell bodies in the peripheral nervous system . Ganglia are also known as nerve nodes because they are noticeable as nodular thickenings during dissection. Ganglia are a stage in the evolution of nervous systems that appear for the first time in coelenterates and can be found in all further developed complex animals. In annelids and arthropods , the rope ladder nervous system consists of differentiated larger ganglia that developed into the brain in the course of evolution.

Active substances that influence the excitation of the ganglia are grouped together as ganglion blockers or ganglioplegics.

Mammalian ganglia

Classification of the ganglia

Ganglia can be further subdivided according to the type of nerve cells (neurons) that form the ganglion.

Sensitive ganglia contain the nerve cell bodies ( soma ) of sensitive neurons. All spinal cord nerves have sensitive ganglia in the form of the spinal ganglia . They contain pseudounipolar nerve cells and are surrounded by a connective tissue capsule, from which the trabeculae pull into the interior and form a support structure, the stroma . The cranial nerves III and VII to X have such ganglia, the VIII. Cranial nerve but has, unlike the others, bipolar ganglion cells .

Autonomous (vegetative) ganglia are found in the autonomic nervous system . They also have a connective tissue capsule, with the exception of the ganglia in the wall of the intestine ( intramural ganglia ). Autonomous ganglia contain multipolar nerve cells . In contrast to the sensitive ganglia, the autonomic ganglia switch to a second nerve cell via synapses .

List of mammalian ganglia

The following ganglia occur in the mammalian organism:

Ganglia of arthropods and lower animals

Particularly noticeable ganglia occur at the front end of the rope ladder nervous system of arthropods and annelids . According to their position above and below the pharynx, they are called the upper and lower pharynx ganglia .

Ganglion blockers

autonomic ( sympathetic and parasympathetic ) ganglia. These are substances with one or two positively charged groups on a nitrogen atom . They either bind competitively to the nicotine receptor and thus suppress the binding of acetylcholine or noncompetitively to the unspecific cation channel of the nicotine receptor.

Differentiation from basal ganglia

Despite their suffix, basal ganglia cannot be assigned to the ganglia because they are located below the cerebral cortex and thus in the central nervous system (CNS) . To distinguish it, nerve cell body accumulations in the CNS are referred to as kernels (nuclei) , the Latin name Nuclei basales is more unambiguous here than the German equivalent.

See also

Individual evidence

  1. a b c Walther Graumann, Dieter Sasse: } Compact textbook anatomy . tape 4 . Schattauer, Stuttgart 2005, ISBN 978-3-7945-2064-0 , pp. 393-392 .
  2. ^ A b Winfried Ahne: Zoology: textbook for students of veterinary medicine and agricultural sciences . Schattauer, Stuttgart 2000, ISBN 978-3-7945-1764-0 , pp. 160-161 .
  3. Wolfgang Dauber: Feneis' picture lexicon of anatomy . Georg Thieme, Stuttgart 2005, ISBN 978-3-13-330109-1 .
  4. Heinz Lüllmann, Klaus Mohr, Lutz Hein: Pharmacology and toxicology: Understanding drug effects - using drugs in a targeted manner . Georg Thieme, Stuttgart 2010, ISBN 978-3-13-368517-7 , p. 116 .

Web links

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