what composes the upper GI
- esophagus: UES & LES
- stomach: fundus, body, pylorus
- only the duodenum of the small intestine
describe the 2 sphincters of the esophagus + pathway (4)
- contracted in their relaxed state pathway: 1. food passes/is directed into the esophagus by the UES 2. esophagus 3. food passes LES 4. bolus of food to stomach
name the 3 digestive processes
- cephalic phase
- gastric phase
- intestinal phase
describe the cephalic phase
- occurs in response to a sensory stimulus (smelling food)
describe gastric phase
starts as food or fluids enter the stomach = stimulates the production of mucus and gastric acid
- Goblet cells
- Parietal cells- HCl and intrinsic factor
- –>The proton pump regulates the synthesis of acid
- –>Think of the proton-pump inhibitors!
describe intestine phase
begins when chyme (enzymatically liquified food) is moved to the duodenum
what is the largest GI organ
the small intestine
the mucosal lining of the small intestine is covered with what?
mucosal lining is covered with villi that each contains goblet cells whose function is to release digestive enzymes, secrete mucus, and absorb nutrients
- within each villus, are microvilli: the combination of villi and microvilli can significantly increase the absorption ability of the small intestine
where does the final digestion occur
the small intestine
what is the duodenum of the small intestine function
chyme mixes with bile and pancreatic enzymes
what is the jejunum of the small intestine primary function (5)
absorption of:
- amino acids
- glucose
- iron
- calcium
- fat-soluble vitamins
what is the ileum of the small intestine primary function
reabsorption of Vit B12 and the return of bile acids to the liver
what is GERD
- the most common and most costly GI disorder
- caused by any functional or mechanical factor that decreases the tone (causing it to relax) of the LES
what are some examples of foods that cause GERD, plus 2 that are not foods (8)
- chocolate
- coffee
- alcohol
- fatty meals
- some drugs
- nicotine
- obesity
- pregnancy
describe the pathway of GERD (4)
- The weak or relaxed LES allows the stomach content to move back to the esophagus
- stomach acid irritates the esophageal cells
- delayed gastric emptying to small intestine (gastroparesis) causes stomach distention
- the increased pressure will cause stomach content to back up to the esophagus
describe the pathway of pregnancy and obesity causing GERD
for pregnancy and obesity: the increased intra-abdominal pressure causes backing up of stomach acid into the esophagus
clinical manifestations of GERD (4)
- Most common: dysphagia, heartburn, epigastric pain, regurgitation
- Respiratory complaint – chronic dry cough; asthma; aspiration pneumonia;
The regurgitation of acidic content into the lungs (especially during sleep) can cause nocturnal asthma attack - Increased pain after eating high fat food – they are longer to digest and thereby causing delayed gastric emptying;
- lying flat or bending can aggravate GERD!
what is Dyspepsia
frequent heartburn
treatment for GERD (3)
- avoid triggers
- limit gastric irritant drugs
- proper positioning
what is PUD (3)
- Refers to lesions that affect the lining of the stomach or duodenum
- Severity varies from superficial erosion to complete penetration through the GI wall (“perforation”)
- more common in African-American and Hispanic males
risk factors of developing PUD (4)
- advancing age
- NSAIDs like naproxen, ibuprofen
- H. pylori infection (most common)
- certain tumors (associated with Zollinger-Ellison syndrome)
what is the main pathology of PUD
imbalance between acid production (that can cause wall erosion) and mucus production (that protects the walls from erosion)
what are duodenal ulcers
- most commonly associated with excessive acid or H. pylori infection
- Pts typically complain epigastric pain relieved with food
what are gastric ulcers
- Less frequent than duodenal but more deadly
- This is often associated with malignancy and use of NSAIDs
- Pain is typically worsened by eating!
