A patient is diagnosed with a rare condition that inhinbits the function of G cells in te stomach antrum. Describe the casacading effect this would have on the gastric environment. Explain the relation between gastrin, parietal cells,
chiief cells and mucous cells. Detail the specific roles of hydrolchloric acid (HCL), pepsinogen, and pepsin in the digestive process.
Answer
When food enters the stomach, gastrrin is released. It travels through the blood to stimulate parietal cells to pump out hydrochloric acid (HCl). This acid is crucial because it creates a higihly acidic enviironment.
The chief cells secretes pepsinogen. On its own, pepsinogen cannot digest food. However, once it encounters the low pH created by the HCl from the parietal cells it undergoes a conformational change and becomes pepsin. Once a small amount of pepsin is formed it can also activate more pepsinogen a process called autocatalysis.
While the acid and enzymes are busy breaking down your dinner, the mucous cells are hard at work. They secrete a thick layer of alkaline mucus. Without this, the pepsin and HCl would begin to digest the stomach wall itself, leading to ulcers.