What substance acts to prevent sudden ph changes in bodily fluids?

A buffer is the substance that prevents rapid or large swings in pH. There are two types of buffers; acidic buffers and basic buffers.

Explanation:

A buffer solution is one which resists changes in pH when small quantities of an acid or an alkali are added to it. Acidic buffer solutions An acidic buffer solution is simply one which has a pH less than 7. Acidic buffer solutions are commonly made from a weak acid and one of its salts - often a sodium salt.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.