Sense of course of a working life first attested 1803. v. 1590s, to charge at a tournament, from career (n.). The meaning move rapidly, run at full speed (1640s) is from the image of a horse passing a career on the jousting field, etc. Related: Careered; careering.
Contractions of the stomach muscle, called peristaltic waves, grind, crush and mix the food producing a liquefied substance called chyme.. The pyloric sphincter separates the stomach from the duodenum. This valve keeps food and gastric juices in the stomach until liquefied enough to proceed into the duodenum.
The duodenum is the first of the three parts of the small intestine and continues from the pylorus of the stomach. It is the shortest part of the small intestine, measuring approximately 25 centimeters in length and is also the most important site of digestion as the pancreatic enzymes and bile empty into the duodenum.