DIGESTIVE  (GI) CANCERS

Anatomy :

• GI tract is the muscular tube from the Mouth to the Anus
• Sphincters mark change from organ to organ down the line
• Accesory organs or the GI tract : squirt liquids into the system
• Duedenom – is the most common place for accessory organs (not a good place for surgery)

Functions of GI Tract:

Ingestion : taking in of food

Propulsion : esophagus moves food along through persitalsis

• Peristalsis  - waves that move food along
• Faster movement at the top of the esophagus than at the bottom (moves fast so you can breath again cause when you swallow you stop breathing)
• Intestines also present with propulsion

Digestion : starts in mouth with break down of carbohydrates through saliva

• No digestion in esophagus
• Stomach : digests protein (strong stomach acids)
• Gall bladder produces bile for fat absorption
• Small intestine
• Pancreas
• No digestion in  colon (large intestine)

Absorption:  small intestine is the main site of absorption (must be very carefull when irradiation in this area)

Elimination: large intestine and colon are responsible for elimination of wastes

• Site of water absorption which makes the fecal material

Unites States has a high rate of Colon Cancer and a low incidence of stomach cancer

Japan has a high rate of stomach cancer and a low rate of colon cancer

(polyps – convert to cancer is Gardners Syndrome 100% of the time)