Myelography is an x-ray examination of the spinal canal. A contrast agent is injected through a needle into the space around the spinal cord to display the spinal cord, spinal canal, and nerve roots on an x ray.he purpose of a myelogram is to evaluate the spinal cord and/or nerve roots for suspected compression. Pressure on these delicate structures causes pain or other symptoms. A myelogram is performed when precise detail about the spinal cord is needed to make a definitive diagnosis.
This is one of the only countries that doesnât touch the Pacific Plate. Instead it lies along the border of the Nazca and South American plates but is still considered to be part of the Ring of Fire. Chile records high levels of rainfall that add to earthquakes and tsunamis as natural disasters to be feared here. Chilean natural disasters include:
Did you know that most of the active volcanoes on Earth are located underwater, along the aptly named Ring of Fire in the Pacific Ocean? The Ring of Fire includes more than 450 volcanoes. It stretches for nearly 25,000 miles, running in the shape of a horseshoe (as opposed to an actual ring) from the southern tip of South America, along the west coast of North America, across the Bering Strait, down through Japan, and into New Zealand. The Ring of Fire is the result of plate tectonics. Much of the volcanic activity occurs along subduction zones which are convergent plate boundaries where two tectonic plates come together. The heavier plate is shoved (or subducted) under the other plate. When this happens, melting of the plates produces magma. The magma rises up through the overlying plate, erupting to the surface as a volcano.