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.
Duodenum is the first part of small intestine that joints the stomach at the pylorus. It is a C-shaped tube, about 10 inches long. It lies between the stomach and jejunum and is very important because it receives the openings of the bile and pancreatic ducts.