Nervous System. All mental and physical activities are controlled or mediated by the brain and the nervous system. Voluntary actions originate in the brain and the nerves carry the information to other parts of our body.The nervous system relies upon a correct chemical balance in the body.ervous System. All mental and physical activities are controlled or mediated by the brain and the nervous system. Voluntary actions originate in the brain and the nerves carry the information to other parts of our body.
From Wikipedia, the free encyclopedia. Letts is a city in Louisa County, Iowa, United States established in 1855. The population was 384 at the 2010 census. It is part of the Muscatine Micropolitan Statistical Area. The name is from local benefactor, Maddison Letts.
Marion County is a county in Iowa. It covers 571 square miles (365,171 acres), which represents less than one percent of the state total. Of the 99 counties in Iowa, Marion County ranks 22nd in terms of the size of its population (33,294, according to 2015 Census estimates). Manufacturing and related services provide the main economic inputs to Marion County.