Tag: bio-chemistry

The small intestine is the primary site for both the chemical digestion of food and the absorption of nutrients into the bloodstream. While the stomach begins protein digestion, the vast majority of nutrient uptake occurs in the small intestine.

Vomiting is a reflex action typically triggered by irritation or distension of the stomach or the upper small intestine (duodenum). It is controlled by the vomiting center in the medulla oblongata, not the hypothalamus.

Secretin is a hormone released by the S cells of the duodenum in response to low pH (acidic chyme) entering from the stomach. It stimulates the pancreas to release bicarbonate-rich fluid to neutralize the acid.

Peyer's patches are organized lymphoid follicles found in the submucosa of the ileum, which is the distal portion of the small intestine. They play a critical role in immune surveillance of the intestinal lumen.

Enterokinase (also known as enteropeptidase) is an enzyme that activates trypsinogen into trypsin. Without trypsin, other pancreatic proteases cannot be activated, leading to a severe failure in protein digestion.

The small intestine is divided into three parts in order: the duodenum (first), the jejunum (middle), and the ileum (last). The duodenum receives chyme from the stomach.

Bile salts are actively reabsorbed in the final part of the small intestine, known as the terminal ileum, returning to the liver via enterohepatic circulation. Most other basic nutrients like glucose and fats are primarily absorbed earlier in the duodenum and jejunum.

The small intestine consists of the duodenum, jejunum, and ileum. The jejunum is the middle segment located between the duodenum and the ileum.

The hepatopancreatic duct (ampulla of Vater) enters the duodenum and its opening is controlled by the sphincter of Oddi, which regulates the flow of bile and pancreatic juice.