Peptic Ulcer Disease and Related Disorders Flashcards
Describe PUD in terms of its relationship to fasting vs meal intake
term for this symptom complex: burning epigastric pain exacerbated by fasting and improved with meals
parietal cell, also known as the ______
oxyntic cell
H+,K+-adenosine triphosphatase (ATPase) is expressed in what part of what cell
tubulovesicle membrane of parietal/oxyntic cell
first line of defense of gastric mucosa
mucus-bicarbonatephospholipid layer,
The ____ functions as a nonstirred water layer impeding diffusion of ions and molecules such as pepsin.
mucous gel
Bicarbonate forms a pH gradient ranging from ____ at the gastric luminal surface and reaching ____along the epithelial cell surface.
Bicarbonate forms a pH gradient ranging from 1 to 2 at the gastric luminal surface and reaching 6–7 along the epithelial cell surface.
The mucosal defense system can be envisioned as a three-level barrier, composed of …. (3)
- preepithelial
- epithelial
- subepithelial elements
Surface epithelial cells generate____ that prevent protein denaturation and protect cells from certain factors such as increased temperature, cytotoxic agents, or oxidative stress
heat shock proteins
If the preepithelial barrier were breached, gastric epithelial cells bordering a site of injury can migrate to restore a damaged region. This process is termed…
restitution
____ is the key component of the subepithelial defense/repair system, providing HCO3 − , which neutralizes the acid generated by the parietal cell.
An elaborate microvascular system within the gastric submucosal layer
Prostaglandins are derived from what substance/chemical
esterified arachidonic acid
A key enzyme that controls the rate-limiting step in prostaglandin synthesis is ____
cyclooxygenase (COX)
This COX isoform is expressed in a host of tissues, including the stomach, platelets, kidneys, and endothelial cells
vs
this COX isoform is expressed in macrophages, leukocytes, fibroblasts, and synovial cells.
COX-1
vs
COX-2
the expression of THIS COX ISOFORM is inducible by inflammatory stimuli
COX-2
The beneficial effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on tissue inflammation are due to inhibition of what COX isoform….
COX-2
the toxicity of NSAIDS (e.g., GI mucosal ulceration and renal dysfunction) is related to inhibition of WHAT COX ISOFORM
COX-1
Selective COX-2 inhibitors have had adverse effects on the cardiovascular (CV) system, leading to increased risk of myocardial infarction. Therefore, the U.S. Food and Drug Administration (FDA) has removed TWO OF THESE AGENTS from the markeT
- valdecoxib
- rofecoxib
What are the two principal gastric secretory products capable of inducing mucosal injury.
- HCl
- pepsinogen
Acid secretion should be viewed as occurring under basal and stimulated conditions. Basal acid production highest levels occurring during the ____and lowest levels during the ____ hours.
Basal acid production highest levels occurring during the NIGHT and lowest levels during the MORNING hours.
2 principal contributors to basal acid secretion
- Cholinergic input via the vagus nerve
- histaminergic input from local gastric sources
Stimulated gastric acid secretion occurs primarily what three phases based on the site where the signal originates
- cephalic
- gastric
- intestinal
cephalic phase stimulates gastric secretion via the WHAT nerve.
via the vagus nerve
When is the gastric phase activated
. The gastric phase is activated once food enters the stomach
The last phase of gastric acid secretion (intestial )is initiated WHEN…
as food enters the intestine
The last phase of gastric acid secretion (intestial )is mediated by (2)
mediated by luminal distention and nutrient assimilation.
This substance is released from endocrine cells found in the gastric mucosa (D cells) in response to HCl. This substance can inhibit acid production by both direct (parietal cell) and indirect mechanisms
somatostatin
the appetite-regulating hormone
Ghrelin
Ghrelin is expressed in what cells….
Gr cells in the stomach
acid-secreting parietal cell is located in what gland
oxyntic gland
Give at least 3 substances that are stimulants of acid secretion together with their receptors…
- histamine (H2)
- gastrin (cholecystokinin 2/gastrin receptor)
- acetylcholine (muscarinic, M3 )
Binding of histamine to the H 2 receptor leads to activation of ____ and ____ pathways in turn resulting in an increase in cyclic adenosine monophosphate (AMP) and intracellular calcium respectively
Binding of histamine to the H 2 receptor leads to activation of adenylate cyclase and the phosphoinositol pathways in turn resulting in an increase in cyclic adenosine monophosphate (AMP) and intracellular calcium respectively.
Activation of the gastrin and muscarinic receptors results in activation of the protein kinase C/phosphoinositide signaling pathway.
Activation of the gastrin and muscarinic receptors results in activation of the ____ signaling pathway.
Binding of histamine to the H 2 receptor leads to activation of adenylate cyclase and the phosphoinositol pathways in turn resulting in an increase in cyclic adenosine monophosphate (AMP) and intracellular calcium respectively.
Activation of the gastrin and muscarinic receptors results in activation of the protein kinase C/phosphoinositide signaling pathway.
Parietal cells also express receptors for ligands that inhibit acid production . Give 4 examples….
Parietal cells also express receptors for ligands that inhibit acid production
* glucagon-like peptide-1
* prostaglandins
* somatostatin
* EGF
This enzyme is responsible for generating the large concentration of H+
H+ ,K+ -ATPase
This cell, found primarily in the gastric fundus, synthesizes and secretes pepsinogen
Chief cell
the inactive precursor of the proteolytic enzyme pepsin.
Pepsinogen
The ____ leads to cleavage of the inactive precursor pepsinogen to pepsin
The acid environment within the stomach leads to cleavage of the inactive precursor to pepsin
- Level of pH required for pepsin activity
- Pepsin activity is significantly diminished at a pH of ____
- and irreversibly inactivated and denatured at a pH of ____
- pH < 2
- pH 4
- pH 7 or more
Ulcers are defined as breaks in the mucosal surface ____mm in size, with depth to the ____.
Ulcers are defined as breaks in the mucosal surface >5 mm in size, with depth to the submucosa.
most common risk factors for PUD (2)
H. pylori and NSAIDs
peak incidence of Gastri ulcer is reported in the WHAT decade
GUs tend to occur later in life than duodenal lesions,
with a peak incidence reported in the sixth decade
DUs occur most often in the WHAT PART of the duodenum
DUs occur most often in the first portion of the duodenum
The base of the duodenal ulcer often consists of a zone of ____
eosinophilic necrosis with surrounding fibrosis
Malignant DUs are common. True or False
False.
Malignant DUs are extremely rare
GUs can represent a malignancy
and should be biopsied WHEN
GUs can represent a malignancy
and should be biopsied upon discovery.
Benign GUs are most often found AT WHAT PART OF THE STOMACH
Benign GUs are most often found distal to the junction between the antrum and the acid secretory mucosa
Differentiate gastric output in GU vs DU
GU - normal or decreased
DU - increased
Location of Types I to IV of GU
- Type I - gastric body
- Type II - antrum
- Type III - within 3 cm of the pylorus
- Type IV - cardia
Different the 4 types of GU in terms of gastric acid output production
- Type I - low gastric acid production
- Type II - low to normal
- Type III - normal or high gastric acid prod
- Type IV - low gastric acid prod
Type of GU that is commonly accompanied by DU
type III
The first step in infection by H. pylori is dependent on the bacteria’s motility and its ability to produce ____
urease
Two factors that p pose to higher colonization rates of H pylori
- poor socioeconomic status
- less education
Mode of Transmission of H. pylori
oral-oral or fecal-oral route
H. pylori infection is virtually always associated with a
chronic active gastritis, but only 10–15% of infected individuals develop frank peptic ulceration
true or false
True
This substacne allows the bacteria to reside in the acidic stomach
urease
Urease, which allows the bacteria to reside in the acidic stomach, generates ____ , which can damage epithelial cells.
NH3
H. pylori makes ____ and ____ that break down the glycoprotein lipid complex of the mucous gel, thus reducing the efficacy of this first line of mucosal defense.
H. pylori makes proteases and phospholipases that break down the glycoprotein lipid complex of the mucous gel, thus reducing the efficacy of this first line of mucosal defense.
H. pylori expresses ____, which facilitate attachment of the bacteria to gastric epithelial cells.
H. pylori expresses adhesins (OMPs like BabA), which facilitate attachment of the bacteria to gastric epithelial cells.
GUs are associated with H. pylori–induced pangastritis
True or False
True
First-degree relatives of DU patients are three times as likely to develop an ulce
True or False
True
personality traits associated with PUD
neuroticism