Gastrointestinal tract is hollow muscular tube from esophagus to anus. Organs have four layers: mucosa, submucosa, muscularis externa, adventitia. Mucosa lines internal passages, submucosa supports mucosa with blood vessels
Duodenum is a 10" c-shaped tube joining stomach to jejunum. Divided into four parts: first 2", second 3", third 4", and fourth 1". Receives bile and pancreatic ducts opening. Mostly retroperitoneal except first and last inches
The ileum is the final section of the small intestine in higher vertebrates. It is about 2-4 meters long in humans with pH between 7 and 8. The ileum is suspended in the mesentery with blood vessels and nerves. It has more fat in the mesentery and thinner walls than the jejunum
Jejunum and ileum are parts of the small intestine. Both segments are located in the abdominal cavity. They are connected to the large intestine through the ileocecal valve
Intestines absorb nutrients and run from stomach to anus. Small intestine is 20-25 feet long with high surface area. Small intestine absorbs proteins, lipids, and carbohydrates. Large intestine absorbs water and solidifies waste into stool