 General function: physical /chemical breakdown of foodstuffs so it can be absorbed into the bloodstream and used by the cells/ tissues while it eliminates non-digestible substances produced during metabolism  Digestion: process of changing foodstuffs into usable substances  Absorption: transfer of nutrients into the blood stream

The digestive system’s major parts are the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. Digestion is the process of physically and chemically breaking down food so that it can be absorbed for use by the cells Digestion begins in the mouth* Saliva is the primary juice that gets digestion going

 Involuntary muscle contractions called peristalsis move food down the esophagus through the alimentary canal  This allows you to swallow food, without it food would get stuck in your esophagus.*  Bolus is chewed food & saliva*

 During swallowing, the soft palate and the uvula move superiorly to close off the nasopharynx, preventing food from entering the nasal cavity. When this process fails, the result is called nasal regurgitation.*

 The digestive system involves the alimentary canal (GI tract) and the accessory organs of digestion.  The alimentary canal extends from the mouth to the anus.  Accessory organs are the teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

 During swallowing the tongue pushes food into the pharynx. Contraction of the pharynx pushes food into the esophagus.  Involuntary muscle contractions move food down the esophagus into the stomach.  In the stomach, food is mixed and churned with gastric juices to form a semi-liquid substance called chyme. The hydrochloric acid is what causes the burn when you vomit.*  The colon absorbs most of the water from the chyme. The remaining semi-solid material is called feces.  Feces pass through the colon into the rectum by peristalsis, then out of the body through the anus.

 Food Stays in stomach for 3-4 hours for physical and chemical breakdown*  If you get car sick and need to ride on an empty stomach, and you ate at 8:00am, What is the soonest you can ride in a car? 9am 10am 12pm 2pm  Stomach is located in the LUQ  Large Intestine: 5 feet/2 inches in diameter  Colon, rectum, and anus all serve as a passageway for fecal waste*  Appendix just there.  Small Intestine: Approximately 21 feet long/1 inch in diameter- 80% of absorption occurs here

 Liver  Secretes bile that helps in digestion of fats*  Detoxes alcohol, but is overworked by alcoholism.*  Causes cirrhosis of liver, most life threatening of digestive system.*  largest gland/solid organ of body;  RUQ under diaphragm  Secretes 1 liter of bile /24 hours

 Pancreas  Pear-shaped muscular sac under the liver  Produces digestive enzymes that empty into the duodenum*  Obstruction  icterus and jaundice  Chole/o = gallbladder  Cholecystitis: gallstones = cholesterol and bile salts  Cholecystectomy: removal of GB