Stomach: Anatomy

Overview

The stomach is a muscular sac in the upper abdomen that plays a critical role in digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption.

Functions of the stomach

• Storage of food
• Digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption:
  • Mechanically breaks up food
  • Mixes food with gastric secretions Gastric secretions Gastrointestinal Secretions to produce chyme Chyme Small Intestine: Anatomy
• Slow/controlled emptying of chyme Chyme Small Intestine: Anatomy into the small intestine Small intestine The small intestine is the longest part of the GI tract, extending from the pyloric orifice of the stomach to the ileocecal junction. The small intestine is the major organ responsible for chemical digestion and absorption of nutrients. It is divided into 3 segments: the duodenum, the jejunum, and the ileum. Small Intestine: Anatomy
• Secretion Secretion Coagulation Studies of:
  • Hydrochloric acid Hydrochloric acid A strong corrosive acid that is commonly used as a laboratory reagent. It is formed by dissolving hydrogen chloride in water. Gastric acid is the hydrochloric acid component of gastric juice. Caustic Ingestion (Cleaning Products) ( HCl HCL Hairy cell leukemia (HCL) is a rare, chronic, B-cell leukemia characterized by the accumulation of small mature B lymphocytes that have “hair-like projections” visible on microscopy. The abnormal cells accumulate in the peripheral blood, bone marrow (causing fibrosis), and red pulp of the spleen, leading to cytopenias. Hairy Cell Leukemia):
    • Activates digestive enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes
    • Breaks up connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology in food
    • Destroys bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology and other pathogens
  • Pepsinogen: converted to pepsin Pepsin Pepsin breaks down proteins into proteoses, peptones, and large polypeptides. Proteins and Peptides by HCl HCL Hairy cell leukemia (HCL) is a rare, chronic, B-cell leukemia characterized by the accumulation of small mature B lymphocytes that have “hair-like projections” visible on microscopy. The abnormal cells accumulate in the peripheral blood, bone marrow (causing fibrosis), and red pulp of the spleen, leading to cytopenias. Hairy Cell Leukemia, which digests proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis
  • Mucus: protects gastric cells from the HCl HCL Hairy cell leukemia (HCL) is a rare, chronic, B-cell leukemia characterized by the accumulation of small mature B lymphocytes that have “hair-like projections” visible on microscopy. The abnormal cells accumulate in the peripheral blood, bone marrow (causing fibrosis), and red pulp of the spleen, leading to cytopenias. Hairy Cell Leukemia
  • Intrinsic factor Intrinsic factor A glycoprotein secreted by the cells of the gastric glands that is required for the absorption of vitamin B 12 (cyanocobalamin). Deficiency of intrinsic factor leads to vitamin B12 deficiency and anemia, pernicious. Gastritis: essential for absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption of vitamin B₁₂
  • Gastrin Gastrin A family of gastrointestinal peptide hormones that excite the secretion of gastric juice. They may also occur in the central nervous system where they are presumed to be neurotransmitters. Gastrointestinal Secretions: stimulates secretion Secretion Coagulation Studies of HCl HCL Hairy cell leukemia (HCL) is a rare, chronic, B-cell leukemia characterized by the accumulation of small mature B lymphocytes that have “hair-like projections” visible on microscopy. The abnormal cells accumulate in the peripheral blood, bone marrow (causing fibrosis), and red pulp of the spleen, leading to cytopenias. Hairy Cell Leukemia and mucus
  • Ghrelin Ghrelin A 28-amino acid, Acylated, orexigenic peptide that is a ligand for growth hormone secretagogue receptors. Ghrelin is widely expressed but primarily in the stomach in the adults. Ghrelin acts centrally to stimulate growth hormone secretion and food intake, and peripherally to regulate energy homeostasis. Its large precursor protein, known as appetite-regulating hormone or motilin-related peptide, contains ghrelin and obestatin. Glucagonoma (the “hunger hormone”): stimulates appetite and promotes fat storage

Development of the stomach

• Develops from the foregut Foregut Development of the Abdominal Organs
• Begins as a longitudinal tube
• Dorsal wall grows faster than its ventral wall → sac expands posteriorly and to the left → develops a C shape
• Rotates along its longitudinal axis into its final position
• Has a dorsal and ventral mesogastrium Ventral mesogastrium Development of the Abdominal Organs (early mesentery Mesentery A layer of the peritoneum which attaches the abdominal viscera to the abdominal wall and conveys their blood vessels and nerves. Peritoneum: Anatomy attaching the primitive foregut Foregut Development of the Abdominal Organs to the posterior body wall):
  • Dorsal mesogastrium Dorsal mesogastrium Development of the Abdominal Organs → greater omentum Omentum Peritoneum: Anatomy
  • Ventral mesogastrium Ventral mesogastrium Development of the Abdominal Organs → lesser omentum Omentum Peritoneum: Anatomy

Gross Anatomy

General characteristics

• C-shaped sac-like organ
• Internal volume:
  • Approximately 50 mL when empty
  • Up to 4 L when full

Parts of the stomach and anatomic landmarks

• Cardia:
  • Entrance of the stomach
  • Adjacent to the lower esophageal sphincter Lower Esophageal Sphincter Esophagus: Anatomy
• Fundus: dome-shaped region located at the highest point of the stomach, above the cardiac opening
• Body: 
  • Main section of the stomach 
  • Extends from the fundus to the pylorus 
  • Bordered by the lesser and greater curvatures
  • Contains thick folds called rugae
• Pylorus (also called the antrum):
  • Connects to the duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy via the pyloric sphincter
  • Consists of a wider pyloric antrum and narrower pyloric canal
• Lesser curvature:
  • A concave curvature along the medial side of the stomach
  • Runs from the right edge of the esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus: Anatomy to the superior border of the pylorus
• Greater curvature:
  • Convex curvature along the lateral side of the stomach
  • Runs from the left edge of the fundus to the inferior border of the pylorus
• Cardiac notch Cardiac notch Lungs: Anatomy: angle created between the esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus: Anatomy and the fundus
• Angular incisure: notch in the lesser curvature in the pyloric region
• Lumen: space inside the stomach walls

Location

• Upper left quadrant of the peritoneal cavity Peritoneal Cavity The space enclosed by the peritoneum. It is divided into two portions, the greater sac and the lesser sac or omental bursa, which lies behind the stomach. The two sacs are connected by the foramen of winslow, or epiploic foramen. Peritoneum: Anatomy
• Connected to:
  • The esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus: Anatomy at its proximal end
  • The duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy at its distal end

Anatomic relationships

The stomach is in direct contact with a number of other organs, including:

• Diaphragmatic dome → fundus and greater curvature 
• Left lobe of the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy → right and ventral side of the stomach
• Spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen: Anatomy → posterior left half of the stomach
• Tail of the pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas: Anatomy → dorsal side of the stomach
• Transverse colon Transverse colon The segment of large intestine between ascending colon and descending colon. It passes from the right colic flexure across the abdomen, then turns sharply at the left colonic flexure into the descending colon. Colon, Cecum, and Appendix: Anatomy → posterior and inferior surfaces of the body and pylorus
• Left kidney and adrenal gland → posterior surface of the gastric body 

Microscopic Anatomy

Layers of the stomach wall

• Mucosa:
  • Consists of 3 sublayers:
    • Simple columnar epithelium Simple columnar epithelium Surface Epithelium: Histology (innermost lining)
    • Lamina propria Lamina propria Whipple’s Disease
    • Muscularis mucosa
  • Gastric pits:
    • Depressions in the mucosa that lead down into gastric glands within the lamina propria Lamina propria Whipple’s Disease 
    • Open into the lumen
  • Lies in folds, called rugae, when the stomach is empty
  • Rugae stretch and flatten when the stomach is filled.
• Submucosa:
  • Contains the submucosal nerve plexus ( Meissner plexus Meissner plexus One of two ganglionated neural networks which together form the enteric nervous system. The submucous (Meissner’s) plexus is in the connective tissue of the submucosa. Its neurons innervate the epithelium, blood vessels, endocrine cells, other submucosal ganglia, and myenteric ganglia, and play an important role in regulating ion and water transport. Gastrointestinal Neural and Hormonal Signaling), which controls the muscularis mucosa
  • Made up of connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology
• Muscularis externa:
  • Has 3 layers:
    • Oblique layer (innermost)
    • Circular layer (middle)
    • Longitudinal layer (outer)
  • Contains (and controlled by) the myenteric nerve plexus ( Auerbach plexus Auerbach plexus One of two ganglionated neural networks which together form the enteric nervous system. The myenteric (Auerbach’s) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. Gastrointestinal Neural and Hormonal Signaling) between the longitudinal and circular layers
  • Important for motility Motility The motor activity of the gastrointestinal tract. Gastrointestinal Motility and mechanical digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption 
• Serosa: outer layer of connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology

Gastric glands

General characteristics:

• Mostly exocrine glands Exocrine glands Glands of external secretion that release its secretions to the body’s cavities, organs, or surface, through a duct. Glandular Epithelium: Histology (secrete products into a luminal space rather than the bloodstream)
• Located beneath the gastric pits within the gastric mucosa
• Multiple glands open into a single gastric pit (which opens into the stomach lumen).
• Neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess region: area where the gastric glands open into the gastric pits

Types of glands:

• Cardiac and pyloric glands:
  • Located in the gastric cardia and pyloric regions, respectively
  • Secrete mucus
• Gastric glands:
  • Glands in the fundus and body
  • Contain multiple cell types → multiple secretory products

Types of cells within the glands:

Comprises (from surface to deep): 

• Surface mucous cells Mucous cells Glandular Epithelium: Histology:
  • Line the gastric pits
  • Simple columnar cells
  • Appear clear on H&E stains
  • Secrete an insoluble mucus:
    • Forms a protective barrier against the acidic environment of the stomach
    • Concentrates bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes in the mucus
• Mucous neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess cells:
  • Located in the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess of the glands, where they join the gastric pits
  • Secrete a soluble mucus
  • Darker-staining nuclei than surface mucous cells Mucous cells Glandular Epithelium: Histology
• Stem cells:
  • Found between the pits and the entrance of the glands
  • Produce new cells to replace both surface mucous cells Mucous cells Glandular Epithelium: Histology in the pits and glandular cells below
  • Stomach epithelial cells are replaced every 3–6 days.
• Parietal Parietal One of a pair of irregularly shaped quadrilateral bones situated between the frontal bone and occipital bone, which together form the sides of the cranium. Skull: Anatomy cells:
  • Located in the middle region of the glands
  • Eosinophilic (stain pink on H&E)
  • Secrete HCl HCL Hairy cell leukemia (HCL) is a rare, chronic, B-cell leukemia characterized by the accumulation of small mature B lymphocytes that have “hair-like projections” visible on microscopy. The abnormal cells accumulate in the peripheral blood, bone marrow (causing fibrosis), and red pulp of the spleen, leading to cytopenias. Hairy Cell Leukemia and intrinsic factor Intrinsic factor A glycoprotein secreted by the cells of the gastric glands that is required for the absorption of vitamin B 12 (cyanocobalamin). Deficiency of intrinsic factor leads to vitamin B12 deficiency and anemia, pernicious. Gastritis
• Chief cells:
  • Most numerous glandular cells
  • Located in the bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance of the glands
  • Basophilic (stain blue on H&E)
  • Secrete pepsinogen and gastric lipase Gastric lipase Digestion and Absorption
• Enteroendocrine cells Enteroendocrine cells Cells found throughout the lining of the gastrointestinal tract that contain and secrete regulatory peptide hormones and/or biogenic amines. Gastrointestinal Secretions:
  • Located in the bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance of the glands
  • Produce different types of hormones Hormones Hormones are messenger molecules that are synthesized in one part of the body and move through the bloodstream to exert specific regulatory effects on another part of the body. Hormones play critical roles in coordinating cellular activities throughout the body in response to the constant changes in both the internal and external environments. Hormones: Overview and Types

Neurovasculature

Arterial blood supply

• Arterial supply is from the celiac trunk.
• Vessels form 2 anastomotic loops along the lesser and greater curvatures.
• Vascular arch of the lesser curvature:
  • Left gastric artery: directly off the celiac trunk
  • Right gastric artery: off the hepatic artery Hepatic artery A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum. Liver: Anatomy (a branch of the celiac trunk)
• Vascular arch of the greater curvature:
  • Left gastroepiploic artery Gastroepiploic artery Abdominal artery that follows the curvature of the stomach. The right gastroepiploic artery is frequently used in coronary artery bypass grafting; myocardial revascularization, and other vascular reconstruction. Gastrointestinal Bleeding: branch off the splenic artery (which is a branch of the celiac trunk)
  • Right gastroepiploic artery Gastroepiploic artery Abdominal artery that follows the curvature of the stomach. The right gastroepiploic artery is frequently used in coronary artery bypass grafting; myocardial revascularization, and other vascular reconstruction. Gastrointestinal Bleeding: branches off the gastroduodenal artery (a branch off the hepatic artery Hepatic artery A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum. Liver: Anatomy)
  • Note: Left and right gastroepiploic arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology are also known as the gastro-omental arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.
• Short gastric arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology:
  • Arise from the terminal splenic artery and the left gastroepiploic artery Gastroepiploic artery Abdominal artery that follows the curvature of the stomach. The right gastroepiploic artery is frequently used in coronary artery bypass grafting; myocardial revascularization, and other vascular reconstruction. Gastrointestinal Bleeding 
  • Supply the fundus of the stomach

Venous drainage

• By homonymous veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology that accompany the arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
• Lesser curvature: right and left gastric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology → drain into the portal vein Portal vein A short thick vein formed by union of the superior mesenteric vein and the splenic vein. Liver: Anatomy
• Greater curvature:
  • Left gastroepiploic vein and the short gastric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology → drain into the splenic vein
  • Right gastroepiploic vein → drains into the superior mesenteric vein

Lymphatic drainage

Lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy draining the stomach are arranged in a complex network.

• Lymph Lymph The interstitial fluid that is in the lymphatic system. Secondary Lymphatic Organs vessels within the mucosa and submucosa collect lymph Lymph The interstitial fluid that is in the lymphatic system. Secondary Lymphatic Organs.
• Drain into immediate surrounding perigastric lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy:
  • Right and left paracardiac lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy
  • Suprapyloric and infrapyloric lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy 
• Perigastric lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy drain into the lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy and vessels, which run along the vasculature supplying the stomach:
  • Left gastric artery
  • Common hepatic artery Hepatic artery A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum. Liver: Anatomy
  • Celiac vessels
  • Splenic artery 
• Ultimately drain into the para-aortic lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy

Innervation

The stomach is innervated by the autonomic nervous system Autonomic nervous system The ANS is a component of the peripheral nervous system that uses both afferent (sensory) and efferent (effector) neurons, which control the functioning of the internal organs and involuntary processes via connections with the CNS. The ANS consists of the sympathetic and parasympathetic nervous systems. Autonomic Nervous System: Anatomy.

• Parasympathetic innervation: anterior and posterior trunks of the vagus nerve Vagus nerve The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx). Pharynx: Anatomy (stimulatory)
• Sympathetic innervation: greater splanchnic nerve (inhibits digestive activity of the stomach)

Clinical Relevance

• Acute gastritis Gastritis Gastritis refers to inflammation of the gastric mucosa. Gastritis may occur suddenly (acute gastritis) or slowly over time (chronic gastritis). Gastritis may be asymptomatic or with symptoms, including burning abdominal pain (which either worsens or improves with eating), dyspepsia, nausea, and vomiting. Gastritis: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation associated with gastric mucosal injury. The most common causes of acute gastritis Gastritis Gastritis refers to inflammation of the gastric mucosa. Gastritis may occur suddenly (acute gastritis) or slowly over time (chronic gastritis). Gastritis may be asymptomatic or with symptoms, including burning abdominal pain (which either worsens or improves with eating), dyspepsia, nausea, and vomiting. Gastritis include Helicobacter pylori Helicobacter pylori A spiral bacterium active as a human gastric pathogen. It is a gram-negative, urease-positive, curved or slightly spiral organism initially isolated in 1982 from patients with lesions of gastritis or peptic ulcers in Western Australia. Helicobacter pylori was originally classified in the genus campylobacter, but RNA sequencing, cellular fatty acid profiles, growth patterns, and other taxonomic characteristics indicate that the micro-organism should be included in the genus Helicobacter. It has been officially transferred to Helicobacter gen. Helicobacter infection and immune-mediated reactions, though alcohol, medications (such as NSAIDs NSAIDS Primary vs Secondary Headaches), and ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage can also be causative; frequently the etiology is unknown. Clinical signs and symptoms include vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia, abdominal discomfort/ pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, and heartburn Heartburn Substernal pain or burning sensation, usually associated with regurgitation of gastric juice into the esophagus. Gastroesophageal Reflux Disease (GERD). Endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD) with gastric mucosal biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma is the best tool for diagnosis. 
• Gastric ulcer Gastric ulcer Ulceration of the gastric mucosa due to contact with gastric juice. It is often associated with Helicobacter pylori infection or consumption of nonsteroidal anti-inflammatory drugs (NSAIDS). Peptic Ulcer Disease: defect of the gastric mucosa, extending into its muscular layer, most often in the lesser curvature and antrum of the stomach. The majority of gastric ulcers are caused by H. pylori H. pylori A spiral bacterium active as a human gastric pathogen. It is a gram-negative, urease-positive, curved or slightly spiral organism initially isolated in 1982 from patients with lesions of gastritis or peptic ulcers in Western Australia. Helicobacter pylori was originally classified in the genus campylobacter, but RNA sequencing, cellular fatty acid profiles, growth patterns, and other taxonomic characteristics indicate that the micro-organism should be included in the genus Helicobacter. It has been officially transferred to Helicobacter gen. Helicobacter infection. The most common symptoms are epigastric pain Epigastric pain Mallory-Weiss Syndrome (Mallory-Weiss Tear) that worsens with eating, epigastric fullness, early satiety Early Satiety Bariatric Surgery, fatty-food intolerance, nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics, and occasional vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia. Diagnosis is confirmed with endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD).
• Gastric cancer Gastric cancer Gastric cancer is the 3rd-most common cause of cancer-related deaths worldwide. The majority of cases are from adenocarcinoma. The modifiable risk factors include Helicobacter pylori infection, smoking, and nitrate-rich diets. Gastric Cancer: neoplasm of the stomach. Adenocarcinoma is the most common type, but additional types include lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum and GI stromal and carcinoid tumors Carcinoid tumors Carcinoid tumors are small, well-differentiated, slow-growing neuroendocrine tumors (NET). Carcinoid syndrome describes the signs and symptoms associated with unregulated vasoactive hormone production by neuroendocrine tumors. Carcinoid tumors are most commonly found in the GI and bronchopulmonary tracts. Carcinoid Tumors and Syndrome. Gastric cancer Gastric cancer Gastric cancer is the 3rd-most common cause of cancer-related deaths worldwide. The majority of cases are from adenocarcinoma. The modifiable risk factors include Helicobacter pylori infection, smoking, and nitrate-rich diets. Gastric Cancer typically presents with weight loss Weight loss Decrease in existing body weight. Bariatric Surgery, dysphagia Dysphagia Dysphagia is the subjective sensation of difficulty swallowing. Symptoms can range from a complete inability to swallow, to the sensation of solids or liquids becoming “stuck.” Dysphagia is classified as either oropharyngeal or esophageal, with esophageal dysphagia having 2 sub-types: functional and mechanical. Dysphagia, vague abdominal pain Abdominal Pain Acute Abdomen, nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics, and early satiety Early Satiety Bariatric Surgery. Upper endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD) with biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma is the gold standard for diagnosis. 
• Pyloric stenosis: characterized by hypertrophy and hyperplasia of the pyloric sphincter in the first months of life. Pyloric stenosis is the most common cause of gastric outlet obstruction in infants. Clinical presentation includes postprandial vomiting that is nonbilious and forceful (often described as “projectile” vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia); an olive-shaped mass Olive-Shaped Mass Hypertrophic Pyloric Stenosis may be palpable in the epigastrium Epigastrium Surgical Anatomy of the Abdomen.