Gastrointestinal Tract: Disorders of Motility
According to Ramsay and Carr (2011), the stomach’s main function is food preparation for digestion as well as absorption by the intestines. In the words of the authors, “acid production is the unique and central component of the stomach’s contribution to the digestive process” (Ramsay and Carr, 2011, p. 977). The parietal cells are responsible for the secretion of acid in the stomach. As Lascelles and Donaldson (2012) point out, the relevance of gastric acid in the digestive process cannot be overstated. This is more so the case given that it comes in handy in the creation of a pH that is ideal or favorable for not only pepsin, but also gastric lipase. It is also important to note that the pancreatic bicarbonate secretion is stimulated by gastric acid. It is food that initiates the secretion of acid. In this case, the taste, smell, or even thought of food does have an impact on what Lascelles and Donaldson (2012) refer to as “vagal stimulation of the gastrin-secreting G cells” (103). Once gastrin is in circulation, histamine is released. It is the said histamine that leads to the parietal cells stimulation and the subsequent secretion of acid. This results in a pH drop which in turn leads to somatostatin release by the antral D cells. As a consequence, the release of gastrin is inhibited. As Lascelles and Donaldson (2012)...
To begin with, HCO3 and mucus production leads to the creation of a pH gradient which, in the words of Lascelles and Donaldson (2012) runs “from the gastric lumen (low pH) to the mucosa (neutral pH)” (104). In basic terms, a barrier is created by the mucus to pepsin and acid diffusion. Next, it should also be noted that any acid that diffuses past or beyond the epithelial layer is removed by mucosal blood flow. Excess hydrogen ions, on the other hand, are removed by epithelial cells.
Gastritis, PUD, and GERD, are predisposed by factors that tend to impede or inhibit the mucosal defenses identified above. To begin with, gastritis has got to do with the erosion, irritation, or inflammation of the stomach lining (Taylor, 2012). Gastritis, according to Pooler (2009) could either be grouped as chronic or acute. In essence, acute gastritis, in the words of the author, “is characterized by an acute mucosal inflammatory process, usually transient in nature” (885). As the author further points out, the condition is in most cases associated with bacterial toxins or alcohol, and aspirin as well as other NSAIDs (Pooler, 2009).
On the other hand, when it comes to chronic gastritis, Pooler (2009) points out that the same is “characterized by the absence of grossly visible erosions and the presence…
