DIGESTIVE SYSTEM ACCESSORY ORGANS DISORDERS Unit 4 Internal

DIGESTIVE SYSTEM: ACCESSORY ORGANS &DISORDERS Unit 4 – Internal Systems

DIGESTIVE SYSTEM

FIRST, SOME DIGESTIVE SYSTEM FACTS: Digestive tract is one, long, thin, muscular tube � All parts of the “tube” are lined with muscle! � Why might this be important? (Think about how muscle tissue behaves. . . ) � So it can stretch to accommodate food moving around. All parts of the digestive tract are lined with mucus (some more than others) � Why might this be important? � So food slides down easily; and muscle is protected by mucus from stomach acid and enzymes. The stomach is protected by the lower part of the ribcage? � Why might this be important? � To protect it from being punctured and stomach acid leaking into abdomen.

WHAT ARE ACCESSORY ORGANS? Organs that are involved in digestion, but are not part of the continuous muscular tube of the digestive tract Include: � Liver � Gall bladder � Pancreas

LIVER Very large organ, approx. 3 kg (6. 6 lb) in adult human Produces bile (digestive juices, including many enzymes and salts) to help break down fats and neutralized stomach acid as it enters the intestine “Detoxifier”: Liver cells contain powerful enzymes that break down toxins / chemicals in some of the things we eat (ex. processing food additives, pesticides, alcohol) and medicines Ammonia - a toxic product arising from the digestion of proteins, is converted into the less toxic 'urea' by the liver and then transferred to the kidneys (and removed via urine)

LIVER Liver receives glucose (sugar molecules) from small intestine. Some of this glucose is stored in the liver in a different form (glycogen). During exercise, the liver breaks down stored glycogen into glucose, releases it to bloodstream for use by muscles as a source of energy. Stores iron, vitamin B 12 and copper.

GALL BLADDER Stores bile produced by the liver until it is needed for digestion Approx. 3 -4 tablespoons (50 m. L) of bile stored Bile is released through common bile duct into duodenum (beginning of small intestine)

PANCREAS Embedded in the tissue surrounding the small intestine Looks like “leafy” tissue Secretes digestive juices (enzymes and hormones) to the small intestine that help to break down the carbohydrates, proteins and lipids in chyme Hormones produced here include insulin (regulates metabolism of sugar and fats) Metabolism = break down

DISORDERS OF THE DIGESTIVE SYSTEM Diarrhea: too much water for the large intestine to absorb exists in the stool Some viruses, bacteria and parasites cause increased secretion of fluid as the body tries to flush out invaders

DISORDERS OF THE DIGESTIVE SYSTEM Ulcers: May occur at various locations in the body, but specifically a peptic ulcer is an ulcer in the stomach Peptic ulcer: erosion in the lining of the stomach or duodenum caused by a virus or bacteria (usually bacteria called Heliobacter pylori, or H. pylori)

OTHER QUESTIONS Why does fatty tissue normally accumulate in the belly area? What makes stomach growl?

KEY WORDS: ACCESSORY ORGANS & DISORDERS Liver Gall bladder Pancreas Bile Ammonia Glucose Glycogen Common bile duct Chyme Metabolism Diarrhea Peptic ulcer Acid reflux