SamKat aka Sam Kegley
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Upper gastrointestinal tract
Upper and Lower human gastrointestinal tractThe upper gastrointestinal tract consists of the oesophagus, stomach, and duodenum.[5] The exact demarcation between "upper" and "lower" can vary. Upon gross dissection, the duodenum may appear to be a unified organ, but it is often divided into two parts based upon function, arterial supply, or embryology.
[edit] Lower gastrointestinal tractThe lower gastrointestinal tract includes most of the small intestine and all of the large intestine.[6] According to some sources, it also includes the anus present in human body.[citation needed]
Bowel or intestine
Small intestine, which has three parts:
Duodenum - Here the digestive juices from pancreas (digestive enzymes) and gallbladder (bile) mix together. The digestive enzymes break down proteins and bile emulsifies fats into micelles. Duodenum contains Brunner's glands which produce bicarbonate and pancreatic juice contains bicarbonate to neutralize hydrochloric acid of stomach
Jejunum - It is the midsection of the intestine, connecting duodenum to ileum. Contain plicae circulares, and villi to increase surface area.
Ileum - It has villi, where all soluble molecules are absorbed into the blood (capillaries and lacteals).
Large intestine, which has three parts:
Cecum (the vermiform appendix is attached to the cecum).
Colon (ascending colon, transverse colon, descending colon and sigmoid flexure). The main function of colon is to absorb water, but it also contains bacteria that produce beneficial vitamins like Vitamin K.
Rectum in human body
Anus
The ligament of Treitz is sometimes used to divide the upper and lower GI tracts.[7]
