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 abdominal part of the large intestine is about 1.5 m long. It consists of the caecum, vermiform appendix, colon (ascending, transverse, and sigmoid), and rectum. Three parts of the large intestine form a frame for the small intestine. The large intestine can easily be distinguished from the small intestine by: