Gastroenterology Visual Aids: Full Illustraded

Introduction:
Gastritis and peptic ulcer
Gastritis is a term used to define the inflammation of the gastric mucosa, while peptic ulcer describes an ulceration located in the distal third of the esophagus, the stomach, or the first portion of the duodenum.
Gastritis is defined as an inflammation of the gastric mucosa. Although the signs and symptoms of a patient can generally be used as a guide, the definitive diagnosis of gastritis is done by an endoscopy, not only with the purpose of discovering the lesion but also to rule out other pathologies that can be riskier for the health of the patient.
Antrum with mild inflammatory changes shows patchy reddening and discrete unevenness, as evidenced by irregular highlighting.

Peptic ulcer
Peptic ulcer is a disorder of the digestive tract located generally in the stomach, the duodenum, and less frequently in the distal esophagus. Among the many different factors that can be associated with an increased incidence of peptic ulcers we find spicy foods or drinks such as coffee, tea, or alcohol, cigarette smoking, certain medications, and stressful situations.
More than 50% of patients with peptic ulcer do not experience any significant symptom for two or more years before being checked by a physician. This illustration shows a benign gastric ulcer with a regular and smooth border.

Peptic ulcer complications
The most frequent complications of peptic ulcers are hemorrhage and perforation which, by means of different mechanisms, can be self-limited or cause several clinical presentations ranging from moderate to severe, even putting the life of the patient at risk. A third, less common complication is luminal obstruction.
A peptic ulcer is perforated when the lesion expands, piercing the muscular layers and the serosa. Perforation is more frequent when the ulcerous lesions are located on the anterior walls or curvatures. At the same time, perforated ulcers of the posterior walls can penetrate other structures. This image shows a perforated ulcer of the posterior wall of the first portion of the duodenum.

Esophageal peptic ulcer
The esophagus may sustain the effects of peptic secretion from the reflux of gastric juices as a result of several factors including persistent vomiting and hiatal hernia. The initial injury produces esophagitis (inflammation of the esophageal mucosa) eventually causing an ulcer.

Helicobacter Pylori
Pathogenesis
Helicobacter pylori is a helical shaped, gram-negative bacterium possessing four to six flagella in one of its ends. This bacterium was first isolated in 1983 from gastric epithelium biopsies. Prevalence of H. pylori infection varies considerably according to race, ethnic group and source of infection. The fecal-oral route of transmission is still hypothetical, however, transmission is known to occur via the oral-oral route, as well as via contaminated medical instruments (catheters, endoscopes, biopsy instruments, etc.)
The severity of infection varies according to socioeconomic conditions. H. pylori is infrequent in developed countries, where its incidence in individuals under the age of 40 is low, but as high as 50% of the population in those older than 60. On the other hand, infection rates in underdeveloped countries increase by 10% per year in individuals between 2 and 8 years old.
H. pylori secretes proteins that interact with gastric epithelial cells and attract macrophages and neutrophils causing inflammation. It also secretes urease, which neutralizes acid pH of the stomach, and toxins, which contribute to ulcer formation.
The microorganism adheres to the mucous cells on the gastric surface without invading it. It is found in the gastric antrum, where it recognizes fucosylated blood group antigens known as H and Lewis b. Once on the gastric mucosa,