Gastro Intestinal

1. Gastro Intestinal Rebecca, Jennifer, Kenny, Michael

2. Purpose of GI Tract • Simplest form- tube from mouth to anus • Digestion, absorption, removal of waste  large molecules  small molecules  absorbed into blood

3. Mouth • Chewing breaks down food • Saliva: • Moistens food • amylase enzyme starts digestion by breaking down starch

4. Simple tube connecting mouth to stomach Peristalsis: muscle contractions that push food down through the esophagus Esophagus

5. Stomach • Sphincter: muscular ring that closes end of esophagus to prevent food and fluid from traveling back up

6. An empty adult stomach has a volume of 1/5 cup, but after a large meal, it can expand to more than 8 cups Stomach muscles mix food with acids and enzymes to break it down Glands in the stomach lining produce 3 quarts of digestive juices a day Stomach

7. Stomach cells • Chief cells in Glands: produce pepsinogen, a precursor of the enzyme pepsin • Parietal cells: secrete the hydrochloric acid of the gastric juice • Stomach epithelium: columnar cells • Mucus-producing

8. Chyme • Food ready to leave the stomach is a thick liquid called chyme • The pylorus, a small muscular valve, keeps chyme in the stomach until it’s ready to go

9. Specialized Cells Upper Tract: • Serous- glandular epithelial cells specialized for exocrine enzyme secretion • Mucous- secrete mucous • Taste Buds- columnar epithelial sensory cells in clusters for tasting

10. Three parts of small intestine: Duodenum: first part, C-shaped Jejunum: coiled middle Ileum: leads to large intestine Small Intestine

11. Villi -cover inner wall of small intestine -microscopic -finger-like -used for absorbing nutrients

12. Large Intestine • Functions: • Absorb water • Bacterial fermentation • Feces formation • Parts: • caecum • appendix • colon • rectum

14. Caecum • Small pouch, first part of the large intestine • Accepts and stores processed material from the small intestine and moves it towards the colon. • Mixture of processed material contains: • undigested food (fibre) • a little bit of water • some vitamins • some minerals or salts

15. Appendix • small projection sticking out from caecum • has no known function in humans • Left over from evolution? • Appendicitis: appendix becomes infected or inflamed • removed by surgery

16. Shaped like an upside-down 'U‘ longest part of the large intestine. 4 Sections: Ascending colon: starts at the caecum… Transverse colon Descending colon Sigmoid colon: S-shaped, connects descending colon and rectum. Colon

17. Colon Function • Mixture = feces • fiber • small amounts of water • vitamins • mucus • bacteria • Colon absorbs most of the water, some vitamins and minerals • Bacteria break down materials to support cells lining the colon • Colon muscular movement  feces stored in rectum

18. Absorptive Goblet Enteroendocrine Stem cells (present throughout GI tract) Specialized Intestinal Cells

19. Function Blood flows from hepatic artery (oxygen-rich) and portal vein (contains food) The liver then produces substances for a variety of functions Liver The liver is the largest gland in the body

20. Hepatocytes form bile Regulate blood glucose Get energy from cholesterol and fat detoxify certain drugs and poisons process certainhormones and vitamin D Specialized Liver Cells

21. Kupffer- clean blood Fenestrated- “full of holes,” permit blood plasma flow in certain areas Specialized Liver Cells

22. Pancreas Functions • Neutralizes acid • Breaks down macromolecular nutrients

23. storage stop between the liver and the small intestine. fills with bile (holds ¼ cup), thickens it Gall Bladder

24. Bile • yellowish-green, pasty liquid • contains water, bile salts and acids, pigments, cholesterol, phospholipids, and electrolytes • Breaks up fat

25. Other Enzymes • Pepsin (stomach): breaks down proteins • Pancreatic amylase • Pancreatic lipase • Small Intestine disaccharidases

40. What do scientists believe? • Some scientists believe the disease is caused by an infection of certain bacteria, but there is not enough convincing evidence to prove that the disease is caused by an infection. • Some also believe it is a genetic disease.

41. Main Symptoms • Common - abdominal pain -diarrhea -weight loss • Less Common -poor appetite -fever -night sweats -rectal pain -rectal bleeding

42. Treatments • Treatments can vary depending on the patient’s symptoms and the severity of the disease. If the symptoms are mild or absent, the patient may not need treatment at all.

43. Treatment Goals • 1) induce remissions • 2) maintain remissions • 3) minimize side effects of treatment • 4) improve the quality of life

44. What types of medicine? • Anti-inflammatory agents such as 5-ASA compounds, corticosteroids, or topical antibiotics • Immuno-modulators • Other medications.

45. Abnormalities/Diseases Of the Gastrointestinal System

46. Abnormalities and Diseases • The gastrointestinal system can be affected by various diseases and abnormalities. • These can include colorectal cancer, gastroenteritis (stomach flu), giardiasis, inflammatory bowel disease, intestinal malrotation, irritable bowel system, and pancreatis.

47. Intestinal Malrotation • Results as birth defect where the intestines are not properly positioned during fetus development and the intestines become blocked. • Can lead to other complications such as the formation of Ladd’s bands.

48. Why it happens. • 1 in 500 babies affected. • When the bowel is misaligned during fetal development. • Occurs if the bowel is not properly moved and fails to return to peritoneal cavity in the normal sequence.

49. What does it do? • Causes a volvulus which is an intestinal twisting that can lead to blockage. • Intestinal blockage can cause death of certain sections of the intestines. • Can cause formation of Ladd’s bands. • Is life threatening if not treated.

50. Affected Organs • Large and Small Intestines – become twisted • Ladd’s Bands (blue) – band of tissue formed attaching cecum to abdominal wall • Cecum (black) – becomes displaced (pouch which is beginning of large intestine)