The contents of the stomach enter the small intestine in what form?
The correct answer and explanation is:
The contents of the stomach enter the small intestine in the form of chyme.
Explanation:
When food is swallowed, it passes through the esophagus into the stomach, where it undergoes mechanical and chemical digestion. The stomach’s muscular walls churn the food, mixing it with gastric juices that contain hydrochloric acid and digestive enzymes such as pepsin. This process breaks down the food into a semi-liquid, acidic mixture called chyme.
Chyme is a thick, soupy, partially digested food substance that is highly acidic (pH around 1.5 to 3.5) due to the presence of hydrochloric acid. The acidic environment helps denature proteins and activates enzymes needed for digestion. Once the stomach has processed the food into chyme, it is gradually released into the small intestine.
The pyloric sphincter, a muscular valve at the junction between the stomach and the small intestine (specifically the duodenum, the first part of the small intestine), regulates the flow of chyme. This sphincter opens intermittently to allow small amounts of chyme to enter the small intestine, ensuring the intestine is not overwhelmed and can efficiently continue the digestion process.
In the small intestine, chyme is neutralized by bicarbonate ions secreted from the pancreas to protect the intestinal lining from acidity. Digestive enzymes from the pancreas and bile from the liver further break down nutrients in the chyme. The small intestine’s lining, covered with villi and microvilli, absorbs the nutrients released from chyme into the bloodstream for distribution to the body.
Thus, the transition from stomach to small intestine involves chyme — a carefully regulated semi-liquid form of food that enables optimal digestion and nutrient absorption downstream.