1. Digestive system cont’d

2. Digestive disorders Diarrhea & constipation Ulcers Appendicitis
Irritable bowel syndrome

3. 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

4. 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

5. 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)

6. 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

7. 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

8. 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)

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

10. 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?

11. 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

12. Try this…
Pg. 278, #2, 5 - 6