The vagina is highly acidic. This low pH comes from the microbes that live in female genitalia. On the mucous membranes, those are primarily lactic acid bacteria (from the genus Lactobacillus). These bacteria produce lactic acid, just as they do when they turn milk into yoghurt.
<h3>Estrogen helps keep the vaginal lining thick and supple and encourages the growth of lactobacili.</h3><h3>These bacteria make a substance that keeps the vaginal slightly acidic. The acidity protects the vagina from harmful,disease causing microorganisms. Yeast also may be present in the healthy vagina.</h3>
Explanation: The way the word expenditure as used in this concept is a noun refering to the application of energy as a result of bodily movement. It also talkes about the use of energy
