q15 - raji_321

[ArchivalUser]

A 50-year-old man is taken to the emergency department because he has a developing myocardial infarction. While in the emergency department, the patient begins to vomit. This relatively common reaction to cardiac pain is mediated by the chemoreceptor trigger zone (CTZ) located in which of the following sites?
A. Floor of the 3rd ventricle
B. Floor of 4th ventricle
C. Frontal lobe
D. Medulla
E. Pons
and where is vomiting center..

[ArchivalUser]

The correct answer is B. Vomiting can accompany severe visceral pain involving the chest or abdomen. The vomiting appears to be typically mediated by vagal afferents that relay in the chemoreceptor trigger zone located in the heavily vascularized area postrema in the floor of the fourth ventricle.
The signals from the chemoreceptor trigger zone are received by the vomiting center located in the lateral reticular formation of the medulla.