alleryStart learning →Bicarbonate and phosphate ions buffer saliva. What pH range do they hold it at?
AA pH between 1.5 and 3.5
BA pH between 7.1 and 8.2
CA pH between 7.6 and 8.6
DA pH between 6.35 and 6.85
Answer & Solution
Correct answer: D. A pH between 6.35 and 6.85
1. Saliva is about 95.5 percent water, with ions, enzymes and other substances in the rest.
2. Bicarbonate and phosphate ions act as chemical buffers within that mixture.
3. They hold saliva at a pH between 6.35 and 6.85, which is just on the acidic side of neutral.
4. A pH of 1.5 to 3.5 is the strongly acidic range of stomach contents.
5. The ranges 7.1 to 8.2 and 7.6 to 8.6 belong to pancreatic juice and bile, both alkaline.
_Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 23 "The Digestive System", section 23.3 The Mouth, Pharynx, and Esophagus_
Keep practising The Digestive System
Browse all The Digestive System questions for HPCSA Board Exam, or explore more Anatomy & Physiology topics.
Related questions
Pick the bigger gut numberSend each enzyme to its makerCatch the brush border enzymesFill the digestive cell boardTrace food from mouth to anusAbout how much of the water reaching the small intestine is absorbed there?Vitamin B12 binds intrinsic factor. Where is the resulting complex taken up, and by what mGlucose and galactose enter intestinal cells by co-transport with sodium. How does fructos