Most small-molecule neurotransmitters are stored in small vesicles that range from 40 to 60 nm in diameter and, in electron micrographs, appear to have clear centers. The vesicles that store neuropeptides are larger, ranging from 90 to 250 nm in diameter.
The world's largest concentration of natural sandstone arches. 1  Hike the 1.5 mile trail leading to the base of Delicate Arch to experience one of the most breathtaking vistas in the world. 2  Your family will love the short trails in the Windows Section that lead right up to several massive arches.
The Gateway Arch in St. Louis, Missouri, is a symbol of our country's growth to the West. The Arch is 630 feet wide at its base. It is as wide as it is tall. At 639 feet high, â¦ it is the tallest monument in the United States.