Important features of the gastrointestinal tract
The following are some of the
important features of the human gastrointestinal tract.
1. There is a copious blood
supply.
2. The entire tract is lined
with mucous membrane through which drugs may be readily transferred into the
general circulation.
3. The interior surface of the
stomach is relatively smooth.
4. The small intestine presents
numerous folds and projections.
5. Approximately 8–10 L per day
of fluids are produced or secreted into the gastrointestinal tract and an
additional 1–2 L of fluid is obtained via food and fluid intake.
6. The gastrointestinal tract is
highly perfused by a capillary network, which allows absorption and
distribution of drugs to occur. This immediate circulation drains drug
molecules into the portal circulation, where absorbed drugs are carried to the
liver and may undergo first pass effect.
