Tag: bio-chemistry

The folds of Kerkring (plicae circulares) are permanent folds of the mucosa and submucosa, most prominent in the duodenum and jejunum, which increase the surface area for absorption.

The pyloric sphincter is a band of smooth muscle at the junction between the pylorus of the stomach and the duodenum of the small intestine. It acts as a valve to control the flow of partially digested food (chyme) into the small intestine. The cardiac sphincter guards the opening from the esophagus into the stomach.

The entire small intestine has circular folds of the mucous membrane, the valves' of kerkring These folds are more prominent in the jejunum.

The sphincter of Oddi (or hepatopancreatic sphincter) controls the flow of bile and pancreatic juice into the duodenum. When closed, bile is diverted back to the gallbladder.

Intrinsic factor is a glycoprotein produced by the parietal cells of the stomach, which is essential for the absorption of Vitamin B12 in the ileum.

Peyer's patches are aggregated lymphoid nodules found specifically in the submucosa of the ileum, which is part of the small intestine.

The mucosa of the duodenum contains absorptive cells (enterocytes), goblet cells (secreting mucus), and argentaffin (enteroendocrine) cells, which produce hormones like secretin and CCK.

The ileum is characterized by the presence of Peyer's patches and club-shaped villi. Brunner's glands are a characteristic feature of the duodenum, not the ileum.

Bile salts are synthesized in the liver, stored in the gall bladder, and aid in fat digestion in the small intestine before being actively reabsorbed specifically in the terminal ileum. This process is known as the enterohepatic circulation of bile salts. Other nutrients like glucose and fats are mostly absorbed in the duodenum and jejunum.

The semi-digested, acidic food mass that moves from the stomach into the duodenum is called chyme.