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.
These monoliths have been featured in the cinema and visited by famous movie icons like Indiana Jones, and their beauty and advanced building techniques are still marveled at today. Here is a look at some of the most famous of these pyramids in Mexico, and what they were believed to represent in ancient culture: 7Pyramid of the Niches (El TajÃ­n) wikipedia/Frank C. MÃ¼ller. Founded by the Classic Veracruz culture, El TajÃ­n was an important gulf coast city around 600 â 900 AD.