GI with a little bit of neuro
Brain stem
Vagus nerve
Auerbach's plexus
Greater splanchnic nerve
Esophageal plexus
Peristalsis is the same thing as tonic motor movements of the stomach.
The esophagus, like the stomach, is an acidic environment.
The beginning of the esophageal phase of swallowing is when the upper esophageal sphincter contracts.
Waterbrash often occurs right before vomiting.
Achalasia occurs when the upper esophageal sphincter fails to relax.
Degeneration of Auerbach's plexus
Toxins
Degeneration of vagal fibers
Mallory-Weiss syndrome
Scleroderma
Mallory-Weiss syndrome
Cirrhosis
Hepatitis
GERD
Scleroderma
Leiomyomas are benign
Dysphagia is an early sign of esophageal cancer
Genetic tendency in 50% of cases
Adenocarcinoma from Barrett's is usually distal
Squamous cell carcinoma accounts for half of esophageal cancers
Pepsinogen
Mucus
Gastrin
HCL
Pepsin
Chief cells
Parietal cells
Intrinsic factors
Cardiac glands
G cells
The vagus nerve
Histamine 2
Prostaglandins
Proton pump
Gastrin
Inhibition of acid secretion
Increase blood flow
Increase mucus production
Increase HCO3 secretion
Create a lipid layer to protect from self digestion
Helicobacter pylori infection
Low gastrin levels
Pernicious anemia
Crohn's disease
Tobacco, alcohol or excessive NSAID use
Autoimmune disorder
Atrophy of glandular epithelium
Decreased pepsin
Crohns disease
High gastrin levels
NSAIDS
Increased acid from increased histamine
Decreased pepsinogen from cholinergic stimulation
Helicobacter pylori
Caffeine
It causes an increase in HCL and a decrease in HCO3
95% of duodenal ulcers result from h. pylori infection
Infection decreases gastrin and pepsin secretion
Secretion of urease leads to ammonia and diminished mucus
15% of people with h. pylori infection will get peptic ulcer disease
NSAIDS: cyclooxygenase inhibition decreases prostaglandin synthesis
H. pylori: inflammatory mediators increase HCL, gastrin and pepsin secretion
Zollinger-Ellison: HCL increases secondary to increased pepsin from a mucosal pepsinoma
Gastric ulcers can result from bile reflux
Duodenal ulcers can be freom gastric hypomotility
They occur more often in men than in women
Hypothyroidism is a risk factor
They are not a concern in the Western world
They are more common in people with type O blood
They are often malignant
Curling's ulcer is from increased acid from vagal stimulation
Cushing's ulcer is from decreased blood flow from catecholamines and hypotension
Curling's ulcers often occur following head injury
Cushing's ulcers occur following severe trauma or sepsis
Curling's ulcers are a concern in severe burn patients.
Thyroid disease
Diabetes mellitus
scleroderma
Amyloidosis
Medications
It occurs more often in females than males
Type O blood is a risk factor
50% are in the fundus of the stomach
They are more common in Thailand than the US
Gastric ulcers are not a risk factor
Fats are absorbed in the colon
Magnesium is absorbed in the stomach
Bile salts are aborbed in the jejunum
Electrolytes are absorbed in the colon
Proteins are absorbed in the ileum
Steatorrhea
Anemia
Constipation
Nocturia
Peripheral neuropathy
Absence of strictures
Continuous involvement as opposed to cobblestoning and skip lesions
Primary in the ileum and secondarily in the colon
Presence of rectal bleeding
Exudative and ulcerative inflammation
Small intestine
Cecum
Ascending colon
Descending colon
Sigmoid colon
Crohn's disease
Diverticulosis
Ulcerative colitis
Carcinoma of the colon
Mechanical obstruction
Appendicitis
Peritonitis
Diverticulosis
Crohn's disease
Ulcerative colitis
Produces bile salts
Metabolizes protein, fats and sugars
Stores vitamins and minerals
Converts urea to uric acid
Synthesizes clotting factors