No, Ramen noodles and Udon noodles are two different types. While I don't know anything about the nutritional value of Udon noodles vs. Ramen Noodles, Udon noodles are white and thicker and Ramen is slightly more yellow and thin.
Apparently most Ramen noodles are made from wheat flour, salt, water, and something known as "Kansui" which is some sort of mineral water containing sodium carbonate, potassium carbonate, and traces of phosphoric acid. Some Ramen noodles substitute Kansui for eggs...