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.
Function: Chemical digestion of food and absorption of nutrients into your blood. Longest section of your digestive tract. Your small intestine is around five metres long, making it the longest section of your digestive tract. Although it is longer than your large intestine it has a smaller diameter. This is why it's called the small intestine. Chemical digestion. After food is churned up in your stomach, a sphincter muscle at the end of your stomach opens to squirt small amounts of food into the top of your small intestine. This first section of the small intestine is called the duodenum. Your pancreas releases digestive juices through a duct into your duodenum. This fluid is rich in enzymes that break down fats, proteins and carbohydrates. It also contains sodium bicarbonate which neutralises acid produced in your stomach.