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.
The Aztecs were a Mesoamerican people who lived in what is now Mexico City and the surrounding territory beginning in the 14th century.They established a broad empire that lasted roughly 200 years and which was based on tributes and military conquests.he Aztecs were a Mesoamerican people who lived in what is now Mexico City and the surrounding territory beginning in the 14th century.