Chemoreceptor trigger zone

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The chemoreceptor trigger zone (abbreviated: CTZ) lies in front of the blood-brain barrier in the area postrema on the floor of the fourth ventricle . It is the starting point for the metabolic and medication-induced nausea and, together with the vomiting center, coordinates the development and course of vomiting , which in turn is part of the protective system of the organism.

The fenestrated capillaries of the trigger zone distinguish it from all other areas of the brain and provide the anatomical basis for a quick reaction to toxic trigger substances that flood the blood . It is rich in dopaminergic , histaminergic , serotinergic and cholinergic end neurons, and these offer starting points for an appropriate antiemetic treatment. Also encountered is substance P , which neurokinin receptors acts (NK receptors).

The high density of 5-HT 3 receptors (serotonin) explains the antiemetic effect of 5-HT 3 antagonists , the presence of opioid receptors explains the emetic early effect of opioids , while their antiemetic late effect is due to an inhibitory effect in the vomiting center.

Individual evidence

  1. ^ Enno Freye: Opioids in der Medizin , 8th edition, Springer, 2010
  2. ↑ Navari, Rick, et al. Reduction of Cisplatin-Induced Emesis by a Selective Neurokinin-1 Receptor Antagonist. NEJM, Volume 340: 190-195 January 21, 1999 Number 3
  3. ↑ General and special pharmacology and toxicology Founded by W. Forth, D. Henschler, W. Rummel. Elsevier, Urban & Fischer 10th edition 2009; ISBN 978-3-437-42522-6

See also