Which of the following does not change pH of stomach: September 2011
**Core Concept:** The stomach is a highly acidic environment, maintained by the action of hydrochloric acid (HCl) secretion from chief cells in the gastric glands. pH is a measure of the acidity or alkalinity of a substance. The correct answer should not involve any acid or base that can neutralize the acidity of the stomach.
**Why the Correct Answer is Right:** Hydrochloric acid (HCl) is a strong acid that plays a crucial role in the stomach's acidic environment. It is produced by chief cells in the gastric glands and helps in protein digestion, killing bacteria, and facilitating the absorption of essential nutrients. Therefore, HCl directly contributes to the acidity of the stomach and cannot be considered as a correct answer.
**Why Each Wrong Option is Incorrect:**
A. **Option A: Serotonin (5-HT)** is a neurotransmitter involved in various physiological processes, including gastrointestinal motility and secretion. However, serotonin does not directly alter the pH of the stomach.
B. **Option B: Ethanol** is a weak organic base that could potentially neutralize the acidity of the stomach. However, ethanol is not specifically involved in maintaining the acidic environment of the stomach.
C. **Option C: Glucose** is a simple carbohydrate and does not have the capability to significantly alter the pH of the stomach. Glucose is not directly involved in regulating the gastric acidity.
D. **Option D: Chloride ions (Cl-)** are present in the gastric juice and contribute to the acidic environment of the stomach. Chloride ions are involved in maintaining the pH, but not specifically in neutralizing the acidity.
**Clinical Pearl:** A low-sodium diet can be beneficial for patients with hypertension, but restricting sodium intake too much, known as the "sodium hypothesis," can lead to impaired gastric acid secretion and reduced gastric acidity, which might negatively impact digestion and absorption processes in the stomach.
**Correct Answer:** D. Chloride ions (Cl-) are present in the gastric juice and contribute to the acidic environment of the stomach. Chloride ions are involved in maintaining the pH, but not specifically in neutralizing the acidity.