Physiology Stomach Functions Properties Notes

Functional Anatomy Of Stomach

The stomach is a hollow organ situated just below the diaphragm on the left side in the abdominal cavity. The volume of an empty stomach is 50 ml. Under normal conditions, it can expand to accommodate 1-1.5 liters of solids and liquids. However, it is capable of expanding still further up to 4 liters.

Parts Of Stomach:

In humans, the stomach has four parts:

1. Cardiac region
2. Fundus
3. Body or corpus
4. Pyloric region.

Read And Learn More: Medical Physiology Notes

1. Cardiac Region: It is the upper part of the stomach where the esophagus opens. The opening is guarded by a sphincter called the cardiac sphincter which opens only towards the stomach. This portion is also known as the cardiac end.

2. Fundus: It is a small dome-shaped structure. It is elevated above the level of the esophageal opening.

3. Body or Corpus: It is the largest part of the stomach forming about 75-80% of the whole stomach. It extends from just below the fundus up to the pyloric region.

4. Pyloric Region:

• The pyloric region has two parts, the antrum, and pyloric canal. The body of the stomach ends in the antrum The junction between the body and the antrum is marked by an angular notch called incisura angularis. Antrum continued as the narrow canal which is called the pyloric canal or pyloric end. The pyloric canal opens into the first part: of the small intestine called the duodenum.
• The opening of the pyloric canal is guarded by a sphincter called the pyloric sphincter. It opens towards the duodenum. The stomach has two curvatures. The one on the right side is lesser curvature and the one on the left side is greater curvature.

Structure Of Stomach Wall

The wall of the stomach is formed by four layers of structures:

• Outer serous layer: Formed by the peritoneum which covers the stomach except at the lesser and greater curvatures, where omenta are attached
• Muscular layer: Made up of three layers of smooth muscle fibers namely, inner oblique, middle circular, and outer longitudinal layers. Auerbach’s plexus is situated between the longitudinal and circular muscle fibers
• Submucous layer: Formed by areolar tissue, blood vessels, lymph vessels, and Meissner’s nerve plexus.
• Inner mucus layer: Lined by mucus-secreting columnar epithelial cells. The gastric glands are situated in this layer. Under resting conditions, the mucosa of the stomach is thrown into many folds. These folds are called rugae. The rugae disappear when the stomach is distended after meals. Throughout the inner mucus layer, small depressions called gastric pits are present. The glands of the stomach open into these pits. The inner surface of the mucus layer is covered by 2 mm thick mucus.

Glands Of Stomach

The glands of the stomach are the gastric glands which are tubular structures made up of different types of cells. Two or more gastric glands join together and open into the stomach cavity via gastric pits.

Classification Of Glands Of The Stomach:

Gastric glands are classified into three types on the basis of their location in the stomach:

1. Fundic glands: Situated in the body and fundus of the stomach. Fundic glands are also called main gastric glands or oxyntic glands
2. Pyloric glands: Present in the pyloric part of the stomach
3. Cardiac glands: Located in the cardiac region of the stomach.

Structure Of Gastric Glands

1. Fundic Glands:

• The fundic glands are considered as the typical gastric glands. These glands are long and tubular glands. Each gland has three parts viz. body, neck, and isthmus.
• Two or more fundic glands open into a common gastric pit, which in turn opens on the surface of the gastric mucosa.

The different cells of the fundic glands are:

• Chief cells or pepsinogen cells
• Parietal cells or oxyntic cells
• Mucus neck cells
• Enterochromaffin (EC) cells or Kulchitsky cells
• Enterochromaffin-like (ECL) cells.

The parietal cells are different from other cells of the gland because of the presence of canaliculi (singular = canaliculus). The parietal cells empty their secretions into the lumen of the gland through the canaliculi.

2. Pyloric Glands: The pyloric glands are short and tortuous in nature. The cells that form the pyloric glands are G cells, mucus cells, EC cells, and ECL cells.

3. Cardiac Glands: Cardiac glands are also short and tortuous in structure with many mucus cells. EC cells, ECL cells, and chief cells are also present in the cardiac glands.

4. Enteroendocrine Cells: Enteroendocrine cells are the hormone-secreting cells present in the glands or mucosa of the gastrointestinal tract, particularly the stomach and intestine. The enteroendocrine cells present in gastric glands are G cells, enterochromaffin cells, and enterochromaffin-like cells.

Functions Of Gastric Glands: The function of the gastric gland is to secrete gastric juice. The secretory activities of different cells of gastric glands and enteroendocrine cells are listed in.

Functions Of Stomach

1. Mechanical Function

1. Storage Function:

• The food is stored in the stomach for a long period, i.e. for 3-4 hours, and emptied into the intestine slowly. The maximum capacity of the stomach is up to 1.5 liters.
• The slow emptying of the stomach provides enough time for proper digestion and absorption of food substances in the small intestine.

2. Formation of Chyme: The peristaltic movements of the stomach mix the bolus with gastric juice and convert it into the semisolid material known as chyme.

Properties And Composition Of Gastric Juice

Gastric juice is a mixture of secretions from different gastric glands.

Properties Of Gastric Juice

Volume                                       : 1200-1500 mL/day.

Reaction                                    : Gastric juice is highly acidic with pH of 0.9-1.2. The acidity of gastric juice is due to the presence of hydrochloric acid.

Specific gravity                        : 1.002-1.004

Composition Of Gastric Juice: Gastric juice contains 99.5% of water and 0.5% solids. The solids are organic and inorganic substances.

Functions Of Gastric Juice

1. Digestive Function:

Gastric juice acts mainly on proteins. The proteolytic enzymes of gastric juice are pepsin and rennin. Gastric juice also contains some other enzymes like gastric lipase, gelatinase, urase and gastric amylase.

Pepsin: The major proteolytic enzyme of gastric juice is pepsin. It is secreted as inactive pepsinogen. Pepsinogen is converted into pepsin by hydrochloric acid which is secreted by parietal cells. The optimum pH for activation of pepsinogen is below 6.

• The action of pepsin: Pepsin attacks the peptide bonds adjacent to aromatic amino acids by hydrolysis. The products of protein digestion by pepsin are proteoses, peptones, and polypeptides. Pepsin also causes curdling and digestion of milk (casein).

Gastric Lipase: Gastric lipase is a weak lipolytic enzyme when compared to pancreatic lipase. It is inactive at a pH below 2.5 and it becomes active only when the pH is between 4 and 5. Gastric lipase is a tributyrin which acts on tributyrin (butter fat) and hydrolyzes it into fatty acids and glycerols.

• Actions of Other Enzymes of Gastric Juice:
  • Gelatinase: Degrades type 1 and type 5 gelatin and type 4 and 5 collagen (which are proteoglycans in meat) into peptides
  • Urase: Acts on urea and produces ammonia
  • Gastric amylase: Degrades starch (but its action is insignificant)
  • Rennin: Curdles milk (present in animals only).

2. Hemopoietic Function:

• The intrinsic factor of Castle present in gastric juice plays an important role in erythropoiesis. It is necessary for the absorption of vitamin B12 (which is called an extrinsic factor) from the Gl tract into the blood. Vitamin B₁₂ is an important maturation factor during erythropoiesis.
• The absence of intrinsic factors in gastric juice causes a deficiency of vitamin B₁₂. And, the deficiency of vitamin B₁₂ leads to pernicious anemia.

3. Protective Function – Function Of Mucus: The thick mucus present in the gastric juice is responsible for the protection of the gastric wall. It is a mucoprotein secreted by mucus neck cells of the gastric glands and surface mucus cells in the fundus, body, and other parts of the stomach.

Mucus:

• Protects the stomach wall from irritation or mechanical injury by virtue of its high viscosity
• Prevents the digestive action of pepsin on the wall of the stomach, particularly gastric mucosa
• Protects the gastric mucosa from hydrochloric acid of gastric juice because of its alkaline nature and its acid combining power.

4. Functions Of Hydrochloric Acid:

Hydrochloric acid present in the gastric juice:

• Activates pepsinogen into pepsin
• Kills some of the bacteria entering the stomach along with food substances — this action is called bacteriolytic action
• Provides acid medium which is necessary for the actions of the hormones.

Mechanism Of Secretion Of Gastric Juice

Secretion Of Pepsinogen:

• Pepsinogen is synthesized from amino acids in the ribosomes attached to the endoplasmic reticulum in chief cells. The pepsinogen molecules are packed into zymogen granules by the Golgi apparatus.
• When a zymogen granule is secreted into the stomach from chief cells, the granule is dissolved and pepsinogen is released into gastric juice. Pepsinogen is activated into pepsin by hydrochloric acid.

Secretion Of Hydrochloric Acid:

• According to Davenport’s theory, hydrochloric acid secretion is an active process that takes place in the canaliculi of parietal cells in gastric glands. The energy for this is derived from the oxidation of glucose.
• In the parietal cells, carbon dioxide combines with water to form carbonic acid. Carbon dioxide is derived from the metabolic activities of the cell. Some amount of carbon dioxide is obtained from blood. The carbonic acid is formed in the presence of the enzyme carbonic anhydrase which is present in high concentration in parietal cells.
• Carbonic acid is the most unstable compound and, immediately it splits into hydrogen ions and bicarbonate ions. The hydrogen ion is actively pumped into the canaliculus of the parietal cell.
• Simultaneously, the chloride ion is also pumped into the canaliculus actively. The chloride is derived from sodium holon-rte in the blood. Now, the hydrogen ion combines wHh chloride ion to form hydrochloric acid. To compensate for the toss of chloride ions, the bicarbonate ion from parietal cesi enters the blood and combines with sodium to form sodium bicarbonate. Thus, the entire process is summarized as.

CO₂ + H₂O + Nacl → HCl + NaHCO₃

Factors Stimulating the Secretion of Hydrochloric Acid:

• Gastrin
• Histamine
• Vagal stimulation.

Factors Inhibiting the Secretion of Hydrochloric Acid:

• Secretin
• Gastric inhibitory polypeptide
• Peptide YY.

Regulation Of Gastric Secretion

Regulation of gastric secretion and intestinal secretion is studied by some experimental procedures.

Methods Of Study

1. Pavlov’s Pouch: Pavlov’s pouch is a small part of the stomach that is incompletely separated from the main portion and made into a small bag-like pouch. Pavlov’s pouch was designed by the Russian scientist Pavlov in dogs during his studies on conditioned reflexes.

Pavlov’s Pouch Procedure:

• To prepare a Pavlov’s pouch, the stomach of an anesthe¬tized dog is divided into a larger part and a smaller part by making an incomplete incision. The mucous mem¬brane is completely divided. A small part of the muscular coat called isthmus is retained. The isthmus connects the two parts.
• The cut edges of major portions are stitched. The smaller part is also stitched, leaving a small outlet. This outlet is brought out through the abdominal wall and used to drain the pouch.

Nerve supply of Pavlov’s pouch: Pavlov’s pouch receives parasympathetic (vagus) nerve fibers through the isthmus and sympathetic fibers through blood vessels.

Use of Pavlov’s pouch: Pavlov’s pouch is used to demonstrate the different phases of gastric secretion, particularly the cephalic phase, and used to demonstrate the role of the vagus in the cephalic phase.

2. Heidenhain’s Pouch

• It is the modified Pavlov’s pouch. The pouch is completely separated from the main portion of the stomach by cutting the isthmus without damaging the blood vessels. The blood vessels are intact. So, Heidenhain’s pouch does not have a parasympathetic supply, but the sympathetic fibers remain intact through the blood vessels.
• Uses of Heidenhain’s pouch: Heidenhain’s pouch is useful to demonstrate the role of sympathetic ner/e and the hormonal regulation of gastric secretion after vagotomy (cutting the vagus nerve).

3. Bickel’s Pouch:

• In this, even the sympathetic nerve fibers are cut by removing the blood vessels. So, Bickel’s pouch is a totally denervated pouch.
• Uses of Bickel’s pouch: Bickel’s pouch is used to demonstrate the role of hormones in gastric secretion.

4. Farrel and Ivy Pouch:

• This pouch is prepared by completely removing the Bickel’s pouch from the stomach and transplanting it in the subcutaneous tissue of the abdominal wall or thoracic wall in the same animal. New blood vessels develop after some days. It is used for experimental purposes when new blood vessels are developed.
• Uses of Farrel and Ivy pouch: This pouch is useful to study the role of hormones during the gastric and intestinal phases of gastric secretion.

5. Sham Feeding: Sham feeding means false feeding. It is another experimental procedure devised by Pavlov to demonstrate the regulation of gastric secretion.

Sham Feeding Procedure:

• A hole is made in the neck of an anesthetized dog
• Esophagus is transversely cut. The cut ends are drawn out through the hole in the neck
• When the dog eats food, it comes out through the cut end of the esophagus
• But the dog has the satisfaction of eating the food. It is called sham feeding.

This experimental procedure is supported by the preparation of Pavlov’s pouch with a fistula from the stomach. The fistula opens to the exterior and it is used to observe the gastric secretion. The animal is used for experimental purposes after a week’s time when healing is completed.

Advantage of sham feeding: It is useful to demonstrate the secretion of gastric juice during the cephalic phase. In the same animal after vagotomy sham feeding does not induce gastric secretion. It proves the role of the vagus nerve during the cephalic phase.

Phases Of Gastric Secretion:

Secretion of gastric juice is a continuous process. But the quantity varies depending upon the time and stimulus. Accordingly, secretion of gastric secretion juice occurs in three different phases:

1. Cephalic phase
2. Gastric phase
3. Intestinal phase.

In human beings, a fourth phase called inter digestive phase exists. All the phases are regulated by neural mechanisms or hormonal mechanisms or both.

1. Cephalic Phase:

• The secretion of gastric juice by the stimuli arising from the head region (cephalus) is called the cephalic phase. This phase of gastric secretion is under nervous control.
• During this phase, gastric secretion occurs even without the presence of food in the stomach. The gastric juice secreted during this phase is called appetite juice.
• The quantity of the juice is less but it is rich in enzymes and hydrochloric acid. The cephalic phase is regulated by nervous mechanisms which operate through reflex action.

Two types of reflexes occur:

1. Unconditioned reflex
2. Conditioned reflex.

1. Unconditioned Reflex: Unconditioned reflex is the inborn reflex. When food is placed in the mouth, it induces salivary secretion. Simultaneously, gastric secretion also occurs.

• Stages of the reflex action:
  • The presence of food in the mouth stimulates the taste buds and other receptors in the mouth
  • The sensory (afferent) impulses from the mouth pass via afferent nerve fibers of glossopharyngeal and facial nerves to the appetite center present in the amygdala and hypothalamus
  • From here, the efferent impulses pass through the dorsal nucleus of the vagus and vagal efferent nerve fibers to the wall of the stomach
  • Acetylcholine is secreted at the vagal efferent nerve endings and it stimulates gastric glands to increase the secretion.

2. Conditioned Reflex: Conditioned reflex is the reflex response acquired by previous experience. The presence of food in the mouth is not necessary to elicit this reflex. By this reflex, the sight, smell, hearing or thought of food which induces salivary secretion induces gastric secretion also.

Stages of reflex action:

• Impulses from the special sensory organs (eye, ear, and nose) pass through afferent fibers of neural circuits to the cerebral cortex
• Thinking of food stimulates the cerebral cortex directly
• From the cerebral cortex, the impulses pass through the dorsal nucleus of the vagus and vagal efferents and reach the stomach wall
• The vagal nerve endings secrete acetylcholine. It stimulates the gastric glands to increase its secretion.

Experimental evidence to prove the cephalic phase:

• The unconditioned reflex of gastric secretion is proved by sham feeding along with Pavlov’s pouch (see above). After vagotomy, sham feeding does not cause gastric secretion. It proves the importance of the vagus nerve in this phase
• The conditioned reflex of gastric secretion is proved by Pavlov’s pouch and bulldog experiment.

2. Gastric Phase:

The secretion of gastric juice, when the food enters the stomach, is called the gastric phase. It is under both nervous and hormonal control. The gastric juice secreted during this phase is rich in pepsinogen and hydrochloric acid. The mechanisms involved in this phase are:

1. The nervous mechanism through local myenteric reflex and vasovagal reflex
2. Hormonal mechanism through gastrin.

The stimuli, which initiate these mechanisms are:

1. Distention of stomach
2. Mechanical stimulation of gastric mucosa by the bulk of food
3. Chemical stimulation of gastric mucosa by the food contents.

1. Nervous Mechanism:

• Local myenteric reflex:
  • Local myenteric reflex is the reflex secretion of gastric juice which is elicited by stimulation of the myenteric nerve plexus in the stomach wall. After entering the stomach, the food particles stimulate the local nerve plexus present in the wall of the stomach.
  • These nerve fibers release additional acetylcholine, which further stimulates the gastric glands to secrete a large quantity of gastric juice. Simultaneously, acetylcholine stimulates G cells to secrete gastrin (see below).
• Vasovagal reflex:
  • The vasovagal reflex is the reflex in which the entrance of food in the stomach causes the secretion of gastric juice. It involves both afferent and efferent vagal fibers. The presence of food in the stomach stimulates the sensory (afferent) nerve endings of the vagus which generate sensory impulses.
  • The sensory impulses are transmitted to the brainstem via sensory fibers of the vagus. Brainstem in turn sends efferent impulses through the motor (efferent) fibers of the vagus back to the stomach and causes the secretion of gastric juice. Since both afferent and efferent impulses pass through the vagus, this reflex is called the vasovagal reflex.

2. Hormonal Mechanism – Gastrin:

• Gastrin is a Gl hormone secreted by the G cells present in the pyloric glands of the stomach. A small amount of gastrin is also secreted in the mucosa of the upper small intestine. In a fetus, it is also secreted by islets of Langerhans in the pancreas. Gastrin is a polypeptide containing G14, G17 or G34 amino acids.
• Gastrin is released when food enters stomach. The mechanism involved in the release of gastrin may be the local nervous reflex or vagovagal reflex. The nerve endings release the neurotransmitter called gastrin-releasing peptide which stimulates the G cells to secrete gastrin.

Actions of gastrin on gastric secretion: Gastrin stimulates the secretion of pepsinogen and hydrochloric acid by the gastric glands.

Experimental evidence of gastric phase: The nervous mechanism of gastric secretion during the gastric phase is proved by Pavlov’s pouch. The hormonal mechanism of gastric secretion is proved by Heidenhain’s pouch, Bickel’s pouch, and Farrel and Ivy’s pouch.

Intestinal Phase: Intestinal phase is the period of secretion of gastric juice when the chyme enters the intestine. When the chyme enters the intestine, initially the gastric secretion increases, and later it stops. The intestinal phase of gastric secretion is under both nervous and hormonal control.

• The initial stage of the intestinal phase: The chyme entering intestine stimulates the duodenal mucosa to release gastrin which is transported to the stomach by blood. There, it increases gastric secretion.
• The later stage of the intestinal phase: When chyme enters the intestine, after the initial increase in the secretion of gastric juice, there is a decrease or complete stoppage of the secretion of gastric juice. The gastric secretion is inhibited by two factors:

1. Enterogastric reflex
2. Gl hormones.

1. Enterogastric reflex: It is a reflex that inhibits the secretory and motor activities of the stomach due to the distention or chemical or osmotic irritation of intestinal mucosa. It is mediated by the myenteric nerve (Auerbach’s) plexus of the enteric nervous system and vagus.

2. Gl hormones: The presence of chyme in the intestine stimulates the secretion of many Gl hormones from intestinal mucosa and other structures. All these hormones inhibit gastric secretion. Some of these hormones inhibit gastric motility also.

• Gl hormones which inhibit gastric secretion:
  • Secretin: Secreted by the presence of acid chyme in the intestine
  • Cholecystokinin: Secreted by the presence of chyme-containing fats and amino acids in the intestine
  • Gastric inhibitory peptide (GIF): Secreted by the presence of chyme containing glucose and fats in the intestine
  • A vasoactive intestinal polypeptide (VIP): Secreted by the presence of acidic chyme in intestine
  • Peptide YY: Secreted by the presence of fatty chyme in intestine
• In addition to these hormones, the pancreas also secretes a hormone called somatostatin during the intestinal phase. It also inhibits gastric secretion.
• Earlier, enterogastrone which was thought to be secreted from duodenal mucosa was considered as the major hormonal inhibitor of gastric secretion. Recent investigations claim that either peptide YY or secretin might be the enterogastrone.
• Anyhow, during the intestinal phase of gastric secretion, the intragastric reflex and intestinal hormones coiteGisvely apply a strong brake on the secretion and motility of the stomach.

Experimental evidence for intestinal phase: The intestinal phase of gastric secretion is demonstrated by Bickel’s pouch and Farrel and Ivy’s pouch.

Interdigestive Phase: The secretion of a small amount of gastric juice in between meals (or during the period of fasting) is called inter digestive phase. Gastric secretion during this phase is mainly due to the hormones like gastrin. This phase of gastric secretion is demonstrated by Farrel and Ivy pouch.

Factors Influencing Gastric Secretion:

Gastric secretion is also influenced by some factors which increase the gastric secretion by stimulating gastric mucosa such as:

1. Alcohol
2. Caffeine.

Collection Of Gastric Juice

In human beings, gastric juice is collected by using Ryle’s tube. The tube is made out of rubber or plastic It is passed through the nostril or mouth and through the esophagus into the stomach. A line is marked in the tube. The entrance of the tip of the tube into the stomach is indicated when this line comes near the mouth. Then, the contents of the stomach are collected by means of aspiration.

Gastric Analysis

For analysis, gastric juice is collected from the patient only in the morning. The analysis of gastric juice is done for the diagnosis of ulcers and other disorders of the stomach. Gastric juice is analyzed for the following:

1. Measurement of peptic activity
2. Measurement of gastric acidity – total acid, free acid (hydrochloric acid), and combined acid.

Methods Of Gastric Analysis: Different methods are used to analyze the gastric juice:

1. Fractional Test Meal (FTM): After overnight fasting, gastric juice is collected. Then, the patient takes a small test meal called a fractional test meal (FTM). The typical test meals are:

• A piece of bread and a cup of tea
• Wheat biscuit and 400 mL of water
• 300 mL of oatmeal gruel.

Fractional gastric analysis: After the ingestion of the test meal, gastric juice is collected at every 15th minute for a period of two and a half hours. All these samples are analyzed for peptic activity and acidity.

2. Nocturnal Gastric Analysis: The patient is given a clear liquid diet at noon and at 5 pm. At 7.30 pm, the tube is introduced patient’s stomach. Then from 8 pm to 8 am, hourly samples of gastric juice are collected and analyzed.

3. Histamine Test: After overnight fasting, the stomach is emptied in the morning by aspiration. Then histamine is injected subcutaneously (0.01 mg/kg). Histamine stimulates the secretion of hydrochloric acid in the stomach. After 30 minutes, 4 samples of gastric juice are collected over a period of one hour at 15-minute intervals and analyzed.

Applied Physiology

1. Gastritis:

• Inflammation of the gastric mucous membrane is called gastritis. It may be acute or chronic. Acute gastritis is characterized by inflammation of superficial layers of mucous membranes and infiltration with leukocytes, mostly neutrophils. Chronic gastritis involves inflam¬mation of even the deeper layers and infiltration with more lymphocytes.
• It results in the atrophy of the gastric mucosa with the loss of chief cells and parietal cells of glands. Therefore, the secretion of gastric juice decreases.

Causes of Acute Gastritis:

• Infection with the bacterium Helicobacter pylori
• Excess consumption of alcohol
• Excess administration of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs)
• Trauma by nasogastric tubes
• Repeated exposure to radiation (rare).

Causes of Chronic Gastritis:

• Chronic infection with Helicobacter pylori
• Long-term intake of excess alcohol
• Long-term use of NSAIDs
• Autoimmune disease.

Gastritis Features:

Features of gastritis are nonspecific. A common feature is abdominal upset or pain felt as a diffused burning sensation. It is often referred to epigastric region. Other features are:

• Nausea
• Vomiting
• Anorexia (loss of appetite)
• Indigestion
• Discomfort or feeling of fullness in the epigastric region
• Belching (process to relieve swallowed air that is accumulated in the stomach).

2. Gastric Atrophy: Gastric atrophy is a condition in which the muscles of the stomach shrink and become weak. The gastric glands also shrink resulting in the deficiency of gastric juice.

• Gastric Atrophy Cause: Gastric atrophy is caused by chronic gastritis called chronic atrophic gastritis. There is atrophy of gastric mucosa including loss of gastric glands. Autoimmune atrophic gastritis also causes gastric atrophy.
• Gastric Atrophy Features: Generally, gastric atrophy does not cause any notice¬able symptoms. However, it may lead to achlorhydria (absence of hydrochloric acid in gastric juice) and pernicious anemia. Some patients develop gastric cancer.

3. Peptic Ulcer: Ulcer means the erosion of the surface of any organ due to shedding or sloughing of inflamed necrotic tissue that lines the organ. Peptic ulcer means an ulcer in the wall of the stomach or duodenum caused by the digestive action of gastric juice. If a peptic ulcer is found in the stomach, it is called a gastric ulcer and if found in the duodenum it is called a duodenal ulcer.

Peptic Ulcer Causes:

• Increased peptic activity due to excessive secretion of pepsin in gastric juice
• Hyperacidity of gastric juice
• Reduced alkalinity of duodenal content
• Decreased mucin content in gastric juice or decreased protective activity in stomach or duodenum
• Constant physical or emotional stress
• Food with excess spices or smoking (classical causes of ulcers)
• Long-term use of NSAIDs (see above) such as aspirin, ibuprofen, and naproxen
• Chronic inflammation due to Helicobacter pylori.

Peptic Ulcer Features:

The most common feature of peptic ulcer is severe burning pain in the epigastric region. In gastric ulcers, pain occurs while eating or drinking. In duodenal ulcers, pain is felt 1 or 2 hours after food intake and during the night. Other symptoms accompanying pain are:

• Nausea
• Vomiting
• Hematemesis (vomiting blood)
• Heartburn (burning pain in the chest due to regurgitation of acid from the stomach into the esophagus)
• Anorexia (loss of appetite)
• Loss of weight.

4. Zollinger-Ellison Syndrome: Zollinger-Ellison syndrome is characterized by the secretion of excess hydrochloric acid in stomach.

Zollinger-Ellison Syndrome Cause: A tumor of the pancreas is the cause of this disorder. The pancreatic tumor produces a large quantity of gastrin which stimulates the parietal cells of gastric glands to secrete a large amount of hydrochloric acid in the stomach.

Zollinger-Ellison Syndrome Features:

• Abdominal pain
• Diarrhea (frequent and watery, loose bowel movements)
• Difficulty in eating
• Occasional hematemesis (see above).