1. Mucosa is the innermost layer. It is the stratified squamous epithelium over lamina propria
and muscularis mucosa. The lamina propria has abundant lymphatic channels.
2. Submucosa contains abundant lympha
Treating Peptic Ulcers
1. Neutralize acid. This can be done with food (buffers acid and increases mucus production) and
with antacids. Antacids neutralize acid and inactivate pepsin. Used for ulcers and GERD.
NaHCO3 is very water
Gastric Secretion and Peptic Ulcers
Glands of the cardiac stomach contain mucus and endocrine cells.
Glands of the fundus and body (oxyntic mucosa) contain mucus cells, parietal cells
(secrete gastric acid and intrinsic factor), chief cells (sec
Colorectal cancer is completely preventable, because it has a long, detectable adenoma stage.
Location influences detectability (further from the rectum, the harder to detect).
Colorectal cancer is the third most common
Disorders of Swallowing
The cervical (1/3) esophagus has pharyngeal constrictors composed of striated muscle.
The thoracic (2/3) esophagus is composed of smooth muscle.
Deglutition = the swallowing sequence
Penetration = bolus enters the larynx
Acute Inflammatory Changes
Neutrophils are the hallmark.
Cryptitis is a neutrophil infiltrate within the crypt epithelium.
Crypt abscess is a collection of neutrophils within the crypt lumen.
Erosions or ulcers cause a fibro
Pathology of Malabsorption
Malabsorption Syndrome = a constellation that includes diarrhea, steatorrhea, weight loss, and
evidence of vitamin deficiencies.
Protein-losing Enteropathy = serum proteins, especially albumin, are lost into the intest
Two major types of Na+ channel: electrogenic and neutral
Electrogenic channels bring in sodium without a balancing anion. This leaves a net
charge difference. Na+ transport may be coupled to glucose, galactose, amino acids.
Gastroparesis, IBS, and Colon Dysmotility
Parasympathetic supply of the gut is a two-neuron pathway with cranio-sacral outflow.
The cranial part is the vagus nerve, which increases propulsive activity, relaxes sphincters, and
Gastritis, Ulceration, and Cancer Pathology
Acute Hemorrhagic and Chemical Gastritis
Not really a gastritis because there is no inflammation.
Characterized by multiple punctate hemorrhages with erosions, edema, and hemorrhage.
There will be thic
Fat Absorption and Malabsorption
Malabsorption is usually from upper GI, pancreas, liver, or stomach dysfunction.
Fat malabsorption causes steatorrhea.
If steatorrhea is suspected, start workup with a 72-hour fecal collection.
Steps in Fat Absor