Bicarbonate bicarbonate – in conjunction with water, hydrogen ions, and carbon dioxide – forms this buffering system, which is maintained at the volatile equilibrium required to provide prompt resistance to pH changes in both the acidic and basic directions. This is especially important for protecting tissues of the central nervous system, where pH changes too far outside of the normal range in either direction could prove disastrous (see acidosis or alkalosis). Bicarbonate also serves much in the digestive system. It raises the internal pH of the stomach, after highly acidic digestive juices have finished in their digestion of food. Bicarbonate also
Digestive biscuit in some varieties. A digestive biscuit averages around 70 calories, although this sometimes varies according to the factors involved in its production. Digestive biscuits are frequently eaten with tea or coffee. Sometimes, the biscuit is dunked into the tea and eaten quickly due to the biscuit's tendency to disintegrate when wet. Digestive biscuits are one of the top 10 biscuits in the United Kingdom for dunking in tea. The digestive biscuit is also used as a cracker with cheeses, and is often included in "cracker selection" packets. In the UK, McVitie's digestive is the best selling biscuit, with 80 million