Changes

Milk of magnesia is used as an antacid to neutralize stomach acid. Hydroxide ions from the Mg(OH)2 combine with acidic hydroxide (H+) ions produced from hydrochloric acid by parietal cells in the stomach to produce water. It is made into capsules and chewable tablets for use against constipation and indigestion ([[:File:UNN_Medical_Geology_Fig_16.png|Figure 16]]).

Milk of magnesia is used as an antacid to neutralize stomach acid. Hydroxide ions from the Mg(OH)2 combine with acidic hydroxide (H+) ions produced from hydrochloric acid by parietal cells in the stomach to produce water. It is made into capsules and chewable tablets for use against constipation and indigestion ([[:File:UNN_Medical_Geology_Fig_16.png|Figure 16]]).

As a laxative, milk of magnesia absorbs fluid from the body, through osmotic pressure, into the lumen of the small intestine while retaining the fluid already in the small intestine (Pradyot, 2002). First, Mg2+ is poorly absorbed from the intestinal tract, so it draws water from the surrounding tissue by osmosis. Not only does this increase the water content, it softens the faeces and increases the volume of faeces in the intestine which naturally stimulates intestinal motility. Furthermore, Mg2+ ions cause the release of cholecystokinin (CCK) which results in intraluminal accumulation of water, electrolytes and increased intestinal motility. This stimulates the nerves of the colon to distend leading to peristalsis culminating in the evacuation of its contents.

As a laxative, milk of magnesia absorbs fluid from the body, through osmotic pressure, into the lumen of the small intestine while retaining the fluid already in the small intestine.<ref>Pradyot, P., 2002. Handbook of Inorganic Chemicals. McGraw-Hill, New York, 186p.</ref> First, Mg2+ is poorly absorbed from the intestinal tract, so it draws water from the surrounding tissue by osmosis. Not only does this increase the water content, it softens the faeces and increases the volume of faeces in the intestine which naturally stimulates intestinal motility. Furthermore, Mg2+ ions cause the release of cholecystokinin (CCK) which results in intraluminal accumulation of water, electrolytes and increased intestinal motility. This stimulates the nerves of the colon to distend leading to peristalsis culminating in the evacuation of its contents.

===Plaster of Paris===

===Plaster of Paris===

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* Pradyot, P., 2002. Handbook of Inorganic Chemicals. McGraw-Hill, New York, 186p.

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* Schamschula, R.C. and Barmes, D.E., 1981. Fluoride and health: Dental Caries, Osteoporosis and Cardiovascular Disease. Annual Review of Nutrient, 1, 427–35.

* Schamschula, R.C. and Barmes, D.E., 1981. Fluoride and health: Dental Caries, Osteoporosis and Cardiovascular Disease. Annual Review of Nutrient, 1, 427–35.

* Selinus, O., 2004. Medical Geology: An Emerging Specialty. Terrae, 1(1), 8-15.

* Selinus, O., 2004. Medical Geology: An Emerging Specialty. Terrae, 1(1), 8-15.