Gastric Disorders Essay Example

Gastric juice is primarily composed of hydrochloric acid, a vital component that aids in killing microorganisms in the GI tract and provide the optimum pH for the working of enzymes. This acid is secreted in the parietal or oxyntic cell, and into the large canaliculi, and the amounts of the acid produced align in direct proportional to the number of the parietal cells. The approximated amount of the hydrochloric acid stimulation is 160Mm, an extrapolation to about 0.8 pH. Once stimulated, the parietal cell membranes undergo dramatic morphological changes. The canalicular membrane increase in number and size, making the Cytoplasmic tubulovesicular membranes which are often in abundance during the resting state of the cell, to virtually disappear. The potassium and chloride conductance channels alongside the proton pump usually reside in the intracellular membrane, but prior to the stimulation, they move and fuse into the canalicular membrane. With all these 'corrosive' processes, the stomach epithelia are intrinsically resistant to the anticipated damage by the gastric acid.

Is your time best spent reading someone else’s essay? Get a 100% original essay FROM A CERTIFIED WRITER!

Order now

Gastric acid secretion takes place as a result of an interplay of inhibitory and stimulatory neurohormonal mechanisms brought about by the presence of food nutrients in the upper GI lumen. It is a response towards hormonal stimulations, among them gastrin, a hormone produced by the G cells in the pyloric mucosa (Dworken, 2016). Two Paracrine messengers produced by the enterochromaffin-like (ECL) cells; histamine and acetylcholine, and a neurocrine messenger in the form of neural synapses also take part in the stimulation and secretion of gastric acid. The natural inhibitors for the secretion of the gastric acid include the hormones cholecystokinin, neurotensin, secretin and glucagon-like peptide and the paracrine release of somatostatin from the gastric D cells. The secretion of the acid is majorly caused by the proton pump, H+/K+ ATPase located in the canalicular membrane.

Even though the other hormones are significant, histamine is considered the most crucial of all. It activates adenylate cyclase on the parietal cells causing an elevation of protein kinase A, PKA. The PKA then phosphorylates cytoskeletal proteins that take part in H+/K+ ATPase transportation to the plasma membrane. The hydrogen ion within the pump is generated via the dissociation of a water molecule in the parietal cells, and the hydroxyl remnant combines with carbon IV oxide to form a bicarbonate ion which is taken across the basolateral membrane in exchange for chloride ions. The deposition of the bicarbonate into blood causes an alkaline tide (slight elevation of blood pH) thereby maintaining the parietal cell intracellular Ph. After the H+/K+ ATPase transportation to the plasma membrane, potassium and chloride ions are moved into the canaliculus lumen through the conductance channel. The H+ is pumped out of the parietal cells into the lumen, while potassium ions are pumped into the parietal cell. Usually, hydrogen ions are osmotically active, and their presence in the canalicular prompts an osmotic gradient across the membrane resulting in the outward movement of water molecules to create the desired pH. The gastric juice product is now 155 mM of HCl, 15 mM of KCl and traces of NaCl.

This entire process, however necessary, must be kept in check through the stimulators and inhibitors, and when this equilibrium is disturbed, the individual suffers from digestive disorders. An excess in the production of the acid, or a limit in its inhibition can cause gastritis, gastroesophageal reflux disease GERD or Peptic ulcer disease PUD. GERD is caused by reflux in the production of hydrochloric acid in the stomach, coupled up by lower sphincter oesophagal relaxation and pressure abnormalities causing the acid and other gastric contents into the oesophagus. Gastritis, on the other hand, is the inflammation or erosion of the stomach wall, resulting in a low stimulation and production of the acid, the enzyme pepsin, and the protective mucus. In some instances when gastritis is caused by h. Pylori, the bacteria accelerates the hormone gastrin, which is an acid stimulator creating a high product of the hydrochloric acid, and thereby the erosion of the mucosa. A persistent erosion of the mucosa, with a corresponding low secretion of the mucal layer, results in peptic ulcer disorders. GERD exists either erosive as in reflux esophagitis and also as a non-erosive reflux disorder, NERD. Women are more likely to suffer from NERD and heartburns (retrosternal burning discomfort) than men (Liu, Cho & Wong). Men also possess a high prevalence of peptic ulcers and stress-induced gastric mucosal injury as compared to the women. This is as a result of the difference in sex hormones which reveal protective effects on the upper gastrointestinal tract. Estrogen, for instance, is believed to have anti-inflammatory effects, making the female tissues more resistant than that of males.

By acknowledging and appreciating the influence that gender has on gastric disorders, the diagnosis, even though essential, must take into account the differences in complexity and prevalence. A physical exam is one of the diagnostic techniques, and by virtue of the gender difference, the physical exam for men might require an extensive endoscopy to reveal the intensity and frequency of the erosion. Other diagnoses include the use of an electrocardiogram, body fluids sample tests and the utilization of the historical background of the individual. The treatment of gastritis encompasses the implementation of behavioural therapy, where the individual is urged to change a lifestyle, either the taking of drugs or specific food, to avoid the causative agent for the condition (Smith, 2017). However, this might hold true for the non-erosive reflux disorder, apparently experienced by women at most. Men have a habit of visiting the doctor when things have worsened, and in some cases, the condition might be chronic. Other treatment approaches will, therefore, be employed like the proton pump inhibitors, histamine blockers, coating agents, among others.

Digestion is a vital physiological process in the human body that ensures the availability of nutrients to the body cells. Among the many enzymes, hormones and processes that take place during this extensive process are the stimulation and production of gastric juice. Taking place at the parietal cells, the production of hydrochloric acid combines a series of neurohormonal stimulations and inhibitions. As important as this process is, any excess or deficit of the produced acids might have adverse effects on the individual. Among the gastric disorders include the GERD, PUD and gastritis. The diagnosis of gastritis, for instance, involves the use of endoscopy and electrocardiograms while the treatment encompasses behavioural and interventional techniques.

References

Dworken, Harvey J (2016). Human digestive system: gastric secretion. Encyclopaedia Britannica Inc. https://www.britannica.com/science/human-digestive-system/Gastric-secretion

Liu, Edgar, Cho Chi & Wong, C Y. Benjamin (2001). Influence of gender difference and gastritis on gastric ulcer formation in rats. Journal of gastroenterology and hepatology. Vol 16. 10.1046/j.1440-1746.2001.02506.x

Smith Lori (2017). Everything you need to know about gastritis. Medical news today. https://www.medicalnewstoday.com/articles/309046.php