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Nausea
and Vomiting
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Angina pectoris
is commonly accompanied by feelings of nausea and sometimes vomiting.
What are the mechanisms for these responses? The short answer
is that no one knows for certain.
Perhaps surprisingly,
the mechanisms involved in vomiting (emesis) are still not completely
determined, and the mechanisms of nausea are even less understood.
Considering the importance of these responses to many pathological
conditions, further research on the mechanisms is needed.
There are
two major sites that initiate the process of emesis
(Figure
14) (Hornby,
2001):
- Vagal
afferents from the gastrointestinal tract; and
- The
chemoreceptor trigger zone in the medulla.
These two
sites will be explored in detail in the screens that follow.
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