Digestive system cont’d

Digestive disorders Diarrhea & constipation

Ulcers

Appendicitis

Irritable bowel syndrome

Diarrhea & Constipation Diarrhea

◦ 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

◦ 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)

◦ 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?

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 bacteriathat DO break down glucose

◦ To help expose surface area of food to bacteria the cow regurgitatesand re-chews “cud” before passing it through the intestine

Try this… Pg. 278, #2, 5 - 6