Thursday, April 25, 2013

Important features of the gastrointestinal tract


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.