Title: The Small and Large Intestines | Biology of Aging
Headings: The Small and Large Intestines
The Small and Large Intestines
The Small Intestine
Structure
Mechanical Digestion in the Small Intestine
Chemical Digestion in the Small Intestine
The Large Intestine
Structure
Subdivisions
Cecum
Colon
Rectum
Anal Canal
Anatomy
Teniae Coli, Haustra, and Epiploic Appendages
Bacterial Flora
Digestive Functions of the Large Intestine
Mechanical Digestion
Chemical Digestion
Absorption, Feces Formation, and Defecation
References

Content: Of particular interest is the hepatopancreatic ampulla (ampulla of Vater). Located in the duodenal wall, the ampulla marks the transition from the anterior portion of the alimentary canal to the mid-region, and is where the bile duct (through which bile passes from the liver) and the main pancreatic duct (through which pancreatic juice passes from the pancreas) join. This ampulla opens into the duodenum at a tiny volcano-shaped structure called the major duodenal papilla. The hepatopancreatic sphincter (sphincter of Oddi) regulates the flow of both bile and pancreatic juice from the ampulla into the duodenum. Small Intestine
The three regions of the small intestine are the duodenum, jejunum, and ileum. The jejunum is about 0.9 meters (3 feet) long (in life) and runs from the duodenum to the ileum. Jejunum means “empty” in Latin and supposedly was so named by the ancient Greeks who noticed it was always empty at death. No clear demarcation exists between the jejunum and the final segment of the small intestine, the ileum. The ileum is the longest part of the small intestine, measuring about 1.8 meters (6 feet) in length. It is thicker, more vascular, and has more developed mucosal folds than the jejunum.