GI- Path- Non-neoplastic diseases of the Stomach Flashcards
The stomach is a muscular of the digestive tract where mechanical and chemical digestion occurs.
dilation
The stomach is divided into four major anatomic regions:
the cardia, fundus, body, and pyloric antrum.
The cardia is lined mainly by mucin-secreting cells that form shallow glands.
foveolar
The antral glands are similar cardia but also contain cells, such as cells, that release gastrin to stimulate luminal acid secretion by parietal cells within the gastric and body.
endocrine
G
fundus
The well-developed glands of the body and fundus also contain cells that produce and secrete digestive enzymes such as
chief
pepsin
Pyloric glands. The pyloric region of the stomach has deep gastric pits (P) leading to short, coiled pyloric glands (G) in the
lamina propria (LP)
Parietal cells stain and chief cells stain .
pink (eosinophillic)
purple (basophillic)
Surface mucous cells secrete fluid containing mucin (yellow)
Mucous neck cells secrete fluid containing mucin (light pink)
Parietal cells secrete and HCl (dark pink)
Chief cells secreted pepsinogen and gastric (purple)
G cells (enteroendocrine cells) secrete into the blood (green)
alkaline
acidic
intrinsic factor
lipase
gastrin
Gastritis results from injury.
- When are present, the lesion is referred to as acute gastritis.
- When cell injury and regeneration are present but inflammatory cells are rare or absent, the term is applied.
mucosal
neutrophils
gastropathy
- When cell injury and regeneration are present but inflammatory cells are rare or absent, the term gastropathy is applied.
- Agents that cause gastropathy include , alcohol, bile, and
NSAIDS
stress-induced injury.
- Both gastropathy and acute gastritis may be asymptomatic or cause variable degrees of epigastric pain, nausea, and vomiting.
- In more severe cases, there may be mucosal , ulceration, hemorrhage, , melena, or, rarely, massive blood loss.
erosion
hematemesis
What is hematemesis and melena?
hematemesis = vomiting of blood
melena = dark sticky feces containing partly digested blood
- The gastric lumen is strongly acidic, with a pH close to , more than 1 million times more acidic than the blood.
- This harsh environment contributes to digestion but also has the potential to damage the
1
mucosa.
What are some normal damaging forces and protective forces in the stomach?
Damaging = gastric acidity, peptic enzymes
Defensive= mucus, bicarb, mucosal blood flow, epithelial regeneration, prostaglandins
Ulcers contain layers of necrotic debris, acute ,
granulation tissue, and (fibrosis).
inflammatory cells
scarring
Multiple mechanisms have evolved to protect the gastric mucosa.
- secreted by surface foveolar cells forms a thin layer of mucus that prevents large food particles from directly touching the epithelium.
- The mucus layer also promotes formation of an “unstirred” layer of fluid over the epithelium that protects the mucosa; it has apH as a result of secretion of ions by surface epithelial cells.
- The rich of the gastric mucosa efficiently buffers and removes that back-diffuse into the lamina propria.
Mucin
neutral
bicarbonate
blood supply
protons
Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX)- dependent synthesis of E2 and I2, which stimulate nearly all of the above defense mechanisms including and bicarbonate secretion, mucosal flow, and restoration.*
prostaglandins
mucus
blood
epithelial
The gastric injury that occurs in uremic (kidney failure) patients and those infected with urease-secreting H. pylori may be due to inhibition of gastric transporters by ions from the urease.
bicarbonate
ammonium
Ingestion of harsh chemicals, particularly acids or bases, either accidentally or in a suicide attempt, leads to severe gastric damage as a result of direct injury to and cells.
mucosal
epithelial
stromal (supportive cells)
• Direct cellular damage also contributes to gastritis induced by excessive consumption, use, and therapy.
alcohol
NSAID
radiation
Agents that inhibit DNA synthesis or the mitotic apparatus, including those used in , may cause generalized mucosal damage due to insufficient epithelial renewal.
cancer chemotherapy
What signifies active gastritis?
presence of neutrophils above the basement membrane in contact with epithelial cells
-note: the epithelium is inbetween the squiggly lines and the neutrophils are circled (inside the lines=active gastritis)
inflammation is preferred over acute inflammation throughout the luminal GI tract, since inflammation may be present in both acute and chronic disease states.
active
What can happen with more severe mucosal damage?
erosions and hemorrhage develop
Concurrent presence of erosion and hemorrhage is termed:
acute erosive hemorrhagic gastritis
severe trauma, extensive burns, intracranial disease, major surgery, serious medical disease, and other forms of severe physiologic stress can lead to what type of gastric injury?
stress-related gastric injury
Over 75% of critically ill patients develop endoscopically visible gastric during the first 3 days of their illness.
lesions
Which type of ulcer is being described?
affecting critically ill patients with shock, sepsis, or severe trauma
stress ulcers
Which type of ulcer is being described?
occur in the proximal duodenum and are associated with severe burns or trauma.
• Curling ulcers
Which type of ulcer is being described?
- arise in the stomach, duodenum, or esophagus of those with intracranial disease and have a high incidence of perforation.
• Cushing ulcers
The pathogenesis of stress-related gastric mucosal injury is most often due to ischemia
This may be caused by systemic or reduced blood flow resulting from stress-induced splanchnic *
local
hypotension
vasoconstriction.
What type of ulcers are thought to be caused by direct stimulation of vagal nuclei resulting in acid hypersecretion?
Cushing ulcers
Systemic may also contribute to mucosal injury by lowering the intracellular pH of cells.
acidosis
mucosal
-Stress-related gastric mucosal injury ranges from shallow erosions caused by superficial epithelial damage to deeper lesions that penetrate the depth of the
- Acute ulcers are rounded and typically less than in diameter.
- The ulcer base frequently is stained brown to black by acid-digested .
mucosa.
1 cm
red blood cells.
Unlike ulcers, which arise in the setting of chronic injury, acute stress ulcers are found in the stomach and are often multiple.
- They are sharply demarcated, with essentially normal adjacent mucosa.
- Healing with complete re-epithelialization occurs days or after the injurious factors are removed.
peptic
anywhere
weeks
Some/Most critically ill patients admitted to hospital intensive care units have histologic evidence of gastric mucosal damage.
Ulcers are associated with nausea, vomiting, melena, and coffee-ground
Prophylaxis with may lessen the impact of stress ulceration, but the most important determinant of outcome is the
of the underlying condition.
Most
hematemesis
proton pump inhibitors
severity
The most common cause of chronic gastritis is infection with
- gastritis represents less then 10% of cases of chronic gastritis but is the most common cause in patients without H. pylori infection.
- Chronic use is a third important cause of gastritis in some populations.
Helicobacter pylori.
Autoimmune
NSAID
Other than H. Pylori, autoimmune issues, and chronic NSAID use, what are 2 other less common causes of chronic gastritis?
radiation injury
chronic bile reflux