What is "chyme"

Chyme \Chyme\, n. [L. chymus chyle, Gr. ? juice, like ?, fr. ? to pour: cf. F. chyme. See Chyle.] (Physiol.) The pulpy mass of semi-digested food in the small intestines just after its passage from the stomach. It is separated in the intestines into chyle and excrement. See Chyle.

early 15c., "bodily fluid;" c.1600 in specific sense of "mass of semi-liquid food in the stomach," from Latin chymus, from Greek khymos, nearly identical to khylos (see chyle) and meaning essentially the same thing. Differentiated by Galen, who used khymos for "juice in its natural or raw state," and khylos for "juice produced by digestion," hence the modern distinction.

n. The thick semifluid mass of partly digested food that is passed from the stomach to the duodenum.

n. a semiliquid mass of partially digested food that passes from the stomach through the pyloric sphincter into the duodenum

Chyme or chymus (; from Greek χυμός khymos, "juice") is the semifluid mass of partly digested food that is expelled by the stomach, through the pyloric valve, into the duodenum (the beginning of the small intestine).

Chyme results from the mechanical and chemical breakdown of a bolus and consists of partially digested food, water, hydrochloric acid, and various digestive enzymes. Chyme slowly passes through the pyloric sphincter and into the duodenum, where the extraction of nutrients begins. Depending on the quantity and contents of the meal, the stomach will digest the food into chyme in anywhere between 40 minutes to a few hours.

With a pH of approximately 2, chyme emerging from the stomach is very acidic. The duodenum secretes a hormone, cholecystokinin (CCK), which causes the gall bladder to contract, releasing alkaline bile into the duodenum. CCK also causes the release of digestive enzymes from the pancreas. The duodenum is a short section of the small intestine located between the stomach and the rest of the small intestine. The duodenum also produces the hormone secretin to stimulate the pancreatic secretion of large amounts of sodium bicarbonate, which then raises pH of the chyme to 7. The chyme then enters the jejunum, where the useful portion of it is transformed into chyle. (As the material moves through the jejunum and ileum, digestion progresses, and the nonuseful portion will continue onward into the large intestine.) The duodenum is protected by a thick layer of mucus and the neutralizing actions of the sodium bicarbonate and bile.

At a pH of 7, the enzymes that were present from the stomach are no longer active. This then leads into the further breakdown of the nutrients still present by anaerobic bacteria, which at the same time help to package the remains. These bacteria also help synthesize vitamin B and vitamin K, which will be absorbed along with other nutrients.