The location in the small intestine where bile and pancreatic juices first mix with the GI tract is the duodenum.
In the digestive system, the duodenum plays a crucial role in receiving these digestive juices from the liver (bile) and the pancreas. This mixing of bile and pancreatic juices with the partially digested food from the stomach helps in further breaking down nutrients such as fats, carbohydrates, and proteins for absorption in the later parts of the small intestine.
The term that describes muscle contraction behind the food and relaxation in front of the food to move it through the digestive system is peristalsis.
Peristalsis is the coordinated contraction and relaxation of muscles in the digestive tract that propels food along the GI tract. This rhythmic movement helps in pushing food from one part of the digestive system to another, allowing for digestion and absorption of nutrients along the way.