GI pathophysiology Review section Bios E-162b, Dec 5, 2010
Feb 23, 2016
GI pathophysiologyReview section
Bios E-162b, Dec 5, 2010
http://en.wikipedia.org/wiki/File:Digestive_system_diagram_edit.svg
Overview of the GI system
http://www.youtube.com/watch?v=Z7xKYNz9AS0
Transit of foodstuffs through the GI system
The wall of the GI tract has several layers
Sphincters control the transit from one section of the GI tract to the next
www.mydr.com.au
Bile and pancreatic secretions are emptied at the same point in the duodenum
www.memorialhermann.org
The enteric nervous system regulates GI activity
mikedaisey.com
GI hormones also regulate GI activity
04340.com
Gastroesophageal reflux is due to an insufficient closure of the lower esophageal sphincter
www.webmd.com
myhealth.ucsd.edu
Hiatus hernias may also cause gastroesophageal reflux
Several factors may cause or aggravate GER
- Young age- Obesity- Pregnancy- Postural changes after eating- Smoking- Peppermint, coffee, alcohol- Diseases of connective tissue
Gastric metaplasia of the esophageal epithelium
GER may lead to Barrett’s esophagus
www.lwjuan.com
Barrett’s esophagus mat lead to esophageal adenocarcinoma
upload.wikimedia.org
The stomach mucosa produces acid, mucus and pepsinogen
Several mediators induce acid secretion
Peptic ulcers come from an imbalance between acid vs. mucus + HCO3
www.yourgicenter.com
H. Pilori is the most common cause
bioweb.uwlax.edu
H. Pilori is the most common cause
upload.wikimedia.org
The digestion of carbohydratesMost dietary carbs are polysaccharides
Cooper GM. The Cell: A Molecular Approach. 2nd edition.
The digestion of carbohydratesAll carbohydrates are converted to
monosaccharides before absorption
salivary a-amilase5% starch Maltose
salivary a-amilase25% starch Maltose
pancreatic a-amilase
70% starch Maltose
The digestion of carbohydratesDisaccharidases at intestinal villi transform
disaccharides in monosaccharides
web.campbell.edu
The digestion of fats
Types of diarrhea
Osmotic
Secretory
Malabsoptive
ie. Lactose intolerance
ie. Cholera
ie. Celiac disease
Inflammatory ie. Chron’s disease
High motility ie. Some medications