Which among..the following is the correct increasing order of pH found in human body ?

The pH scale measures acidity and alkalinity, where lower values indicate higher acidity. Gastric juice is highly acidic, with a mean pH of approximately 2.0, primarily due to hydrochloric acid secretion for digestion. Saliva is slightly acidic to near-neutral, typically ranging from 6.2 to 7.6, with an average value often cited around 6.0 to 6.8 [2]. Human blood is slightly alkaline, maintained within a very narrow and strictly regulated physiological range of 7.35 to 7.45 [1]. Therefore, the correct increasing order of pH (from most acidic to most alkaline) is gastric juice (~2.0), followed by saliva (~6.5), and finally blood (~7.4). This sequence reflects the transition from the highly acidic environment of the stomach to the slightly basic environment of the circulatory system.

Sources

1. [2] https://www.ncbi.nlm.nih.gov/books/NBK482291/
2. [1] https://www.sciencedirect.com/topics/immunology-and-microbiology/stomach-ph