Digestive system cont’d

Digestive disorders Diarrhea & constipation Ulcers Appendicitis Irritable bowel syndrome

Diarrhea & Constipation Watery bowel movements Only called ‘diarrhea’ is passing 3/day for >1 day Predominantly caused by viral, bacterial or parasitic infection called gastroenteritis Treatment = drink water, continue eating, medication Constipation Describes difficult/infrequent bowel movements May progress to fecal impaction/bowel obstruction (possibly death!) Treatment = drink water, laxative/medication

Ulcers Ulcers Discovery… (no need to write down) Inflammation/pitting in stomach wall (causes extreme discomfort, pain and vomiting) Unprotected from acid = further damage Caused by bacteria, Helicobacter pylori Treatment = antibiotics, diet change Discovery… (no need to write down) Barry Marshall & Robin Warren Believed ulcers were caused by bacteria but were not given funding Drank the bacteria to prove it (got ulcers!) 2005 Nobel prize for medicine

Appendicitis Appendicitis Inflammation of appendix due to bacterial infection Can rupture (and cause death!) if not removed laparoscopically 1 in 15 change of happening to you (mostly men afflicted)

IBS & colon cancer Irritable bowel syndrome (IBS) Colon cancer Causes cramping, abdominal pain, bloating, gas, diarrhea/constipation No known cause (maybe stress, maybe microflora, etc.) Treatment = carefully managed diet (not a cure) Colon cancer Cancer of the large intestine Can be detected by blood in stool (red/black) Treatment = surgical removal of section of colon and chemotherapy

Gastrointestinal technologies Colostomy bag (AKA ostomy pouch) Stoma is formed in abdominal wall that provides alternate exit for colon Fecal matter is collected in a replaceable bag instead of passing through the anus

Endoscopy/Colonoscopy An endoscope is a tube-like camera used for observing the inside of a body cavity Endoscopy Internal observations of the upper digestive system (stomach, esophagus) Colonoscopy Internal observations of the large intsestine (colon)

Carnivorous vs Herbivorous digestion Even among similar organisms the structure their digestive system depends on their diet Why do you think these differences exist?

Why is this mechanical digestion important? Birds Birds can eat a variety of foods (insects, worms, berries, seeds, etc.) The crop stores food Most chemical digestion occurs in the stomach The gizzard is filled with gravel/pebbles the bird eats to mechanically digest food stuffs Why is this mechanical digestion important?

Cows/ruminants Cows are ruminant mammals (like sheep, deer, etc.) with a 4-chamebered stomach Mammals can’t digest cellulose - WHY NOT?! New food is cycled to the rumen and reticulum to get a dose of bacteria that DO break down glucose To help expose surface area of food to bacteria the cow regurgitates and re-chews “cud” before passing it through the intestine

Try this… Pg. 278, #2, 5 - 6