Question

In which location do muscarinic receptor antagonists act as chemoreceptor trigger zone blockers?

a. Inner ear
b. Parietal cells
c. Chemoreceptor trigger zone
d. Respiratory system

Answer 1

Muscarinic receptor antagonists block the chemoreceptor trigger zone (CTZ) located in the brain's medulla, which can induce vomiting when activated.

Step-by-step explanation:

Muscarinic receptor antagonists act as chemoreceptor trigger zone (CTZ) blockers in the chemoreceptor trigger zone. This area is located in the medulla near the floor of the fourth ventricle in the brain and is part of the vomiting center. It is responsible for inducing vomiting when activated by certain stimuli, including medications and toxins. These antagonists bind to muscarinic receptors, which are a type of receptor in the cholinergic system. They inhibit the effects of acetylcholine in the respiratory system, leading to a blocking effect in the chemoreceptor trigger zone.