Title: 23.6 The Small and Large Intestines – Anatomy & Physiology
Headings: 23.6 The Small and Large Intestines
23.6 The Small and Large Intestines
Learning Objectives
The Small Intestine
Structure
Histology
Circular folds
Villi
Microvilli
Intestinal Glands
Intestinal MALT
External Website
Mechanical Digestion in the Small Intestine
Chemical Digestion in the Small Intestine
Disorders of the…Small Intestine: Lactose Intolerance
The Large Intestine
Structure
Subdivisions
Cecum
Colon
Homeostatic Imbalances – Colorectal Cancer
Rectum
Anal Canal
Histology
Anatomy
Bacterial Flora
Digestive Functions of the Large Intestine
Mechanical Digestion
Chemical Digestion
Absorption, Feces Formation, and Defecation
External Website
Interactive Link Questions

Content: the superior, descending, horizontal, and ascending duodenum. 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. Figure 23.6.1 – 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.