2 B: Pathology of the Stomach Flashcards
What is Gastritis?
The inflammation of the stomach lining
What is Acute Gastritis?
Transient; most commonly associated w. local irritants like bacterial endotoxins, alcohol, aspirin and NSAIDs
What are the symptoms of acute gastritis?
Anorexia, nausea, emesis, & transient pain & usually disappear once causative agent is removed
What is chronic gastritis?
atrophy of the glandular epithelium of the stomach;
MOST COMMON form of chronic gastritis is H. pylori gastritis
Until early 1980s accepted medical paradigm about ulcers was what?
That ulcers occurred when excess acid damaged the gastric mucosa and that treatment should be aimed at reducing or neutralizing that acid
**It was thought that overproduction of acid was linked to stress
Why does H. pylori survive in the stomach?
B/c it produces the enzyme urease, which generates substances (NH3) that neutralizes the stomach’s acid & enable the bacteria to survive.
**It penetrates the gastric mucosa
H. pylori causes inflammation of what?
Inflammation of the gastric mucosa (gastritis).
***This is asymptomatic and causes Peptic Ulcer Disease (PUD)
What does gastric inflammation lead to ?
Duodenal or gastric ulcers b/c of increased acid secretion
-severe complications include bleeding ulcer and perforated ulcer
H. pylori infects what?
The lower part of the stomach, “antrum”
Note: upper part of stomach = corpus
What occurs within weeks of infection with H. pylori?
Many people develop gastritis
***Most never develop ulcers
What are other risk factors for PUD ?
1) NSAIDs
2) Smoking
3) ethanol
What is a Hiatal Hernia?
Occurs when a portion of the stomach prolapses thru the diaphragmatic or esophageal hiatus
What are the 2 kinds of Hiatal Hernia’s?
1) Paraesophaeal Hiatal Hernia
2) Sliding Hiatal Hernia
What are predisposing factors for a Hiatal Hernia?
1) Muscle weakening and loss of elasticity as people age
2) More common in women b/c of intra-abdominal forces exerted in pregnancy
3) Western fiber-depleted diet leads to a state of chronic constipation and stranding during bowel movement
4) Obesity b/c of increased abdominal pressure
5) Presence of abdominal ascites
What are the results of a Hiatal Hernia?
- May trap a reservoir of gastric contents above the diaphragm, increasing risk for GERD
- Compromise LES function
What produces IF? and what does IF bind to?
Stomach makes it and it binds to Vitamin B12 in the S. intestine
What is IF absorbed by?
Enterocytes of the terminal ileum, from which it is delivered to the bloodstream
What does an inadequate absorption of B 12 cause?
Pernicious anemia
What is Pernicious anemia?
Characterized by the appearance in the bloodstream of large primitive RBC procurers called Megaloblasts
How does RBC appear in pernicious anemia?
- Flimsy membranes and are oval rather than biconcave
- Oddly shaped cells w/ a short life span that can be measured in weeks
What are the oral manifestations of pernicious anemia?
-Erythema and atrophy of the dorsal tongue
-Megalobastic anemia burning macular, erythematous mucosal lesions
secondary to gastric bypass for obesity
How can you resolve lesions in mouth?
B12 injections or “Nascobal” nasal spray
Is the stomach necessary ?
What adaptions must be made, if removed ?
No.. Survival without it is possible
***Pancreatic and small intestinal enzymes are adequate for digestion.
Adaptations:
a) Food must be eaten in small amts, frequently
b) B 12 supplements
c) care should be taken to eat properly cleaned food
What is vomiting?
A forceful explosion of contents of stomach/proximal small intestine
What are the consequences of vomiting?
- acid-base disorders (metabolic alkalosis)
- volume and electrolyte depletion
- malnutrition
- aspiration pneumonia (bacteria colonizing airways)
What are the 3 series of events that occur with vomiting?
1) Nausea
2) Retching “dry heaves”
3) Emesis or vomiting
What is Nausea?
- Associated w/ decreased gastric motility and increased tone in the small intestine
- reverse peristalsis in proximal s. intestine
(Unpleasant and difficult to describe psychological experience )
What is Retching?
- Referes to spasmodic respiratory movements conducted with a closed glottis.
- Also the antrum of the stomach contracts and the funds and cardia relax at the same time
What is emesis?
When gastric and often small intestinal contest are propelled up to and out of the mouth
Emesis results from what events?
1) A deep breath is taken, glottis is closed and larynx is raised to open the upper esophageal sphincter.
2) Soft palate is elevated to close off the posterior nares
3) Diaphragm is contracted snarly downward to create negative pressure in the thorax which opens the esophagus and lower esophageal sphincter
4) Downward movement of the diaphragm, the muscles of the abdominal walls are contracted squeezing the stomach and elevating the intra-gastric pressure.
5) Pylorus is CLOSED and the esophagus relatively OPEN
What are the causes of vomiting?
1) GI tract
2) CNS
3) Therapeutic agents
4) Metabolic disorders
5) pregnancy
How does the GI cause vomiting?
-Bacterial toxins, alcohol, distention or obstruction of organs, pharyngeal irritation
How does the CNS cause vomiting?
-Psychogenic factors (sight, smell, feelings), pain, motion sickness, increased ICP “intra-cranial pressure”
How does Therapeutic agents cause vomiting?
-Cancer chemotherapy, morphine, NSAIDs, antibiotics
How does Metabolic Disorders cause vomiting?
-Ketoacidosis, renal failure
How does Pregnancy cause vomiting?
-Causes unknown, but may involve normal changes, intra-abdominal pressure, or delayed gastric emptying
What are the bilateral vomiting centers?
Commander-in-chief of vomiting (both sides of brain)
Chemoreceptor trigger zone?
Signals arising from the brain. The area located bilaterally on the floor of the 4th ventricle
