Sections: Prologue | Before Lewis & Clark | Lewis & Clark | After Lewis & Clark When Thomas Jefferson sent Lewis and Clark into the West, he patterned their mission on the methods of Enlightenment science: to observe, collect, document, and classify.
Partially digested food, or chyme, from the stomach is mixed with bile from the liver and pancreatic juice from the pancreas to complete its digestion in the duodenum. The jejunum is the middle section of the small intestine that serves as the primary site of nutrient absorption. It measures around 3 feet in length. The ileum is the final section of the small intestine that empties into the large intestine via the ileocecal sphincter.
The small intestine, or small bowel, lies between the stomach and the colon. The small intestine is about 6 m (20 ft) long. Its primary function is to digest and absorb nutrients. The small intestine makes up more than 70% of the length and 90% of the surface area ofthe gastrointestinal (GI) tract. The most common cancerous (malignant) tumors of the small bowel include adenocarcinoma, lymphoma, sarcoma, and carcinoids. In industrialized countries, adenocarcinomas occur most often.