Morphine, like many prescription drugs, may require larger doses for pain control when used for extended periods of time. Over time, the body can develop a tolerance for the medication and will require more medication to experience the same level of effectiveness.
By Kimberly Munro Fri, Mar 18, 2011. The first installment of our Ancient Peru series relates what archaeology has revealed about its first cities and civilizations. The expansive, culturally rich civilizations that existed in the Americas at the time of European contact came as a great surprise to the early Spanish explorers. Most notable were the Aztec empire in Central Mexico and the Incan empire in Peru, both of which controlled great expanses of land and millions of people.
Zapotec civilization. The Zapotec civilization was an indigenous pre-Columbian civilization that flourished in the Valley of Oaxaca in Mesoamerica. Archaeological evidence shows that their culture goes back at least 2,500 years. The Zapotec left archaeological evidence at the ancient city of Monte AlbÃ¡n in the form of buildings, ball courts, magnificent tombs and grave goods including finely worked gold jewelry. Monte AlbÃ¡n was one of the first major cities in Mesoamerica and the center of a Zapotec state that ...