The largest oil spill to occur in the United States so far was the Exxon Valdez spill into Prince William Sound, Alaska, in March 1989. The Exxon Valdez, a medium-sized oil tanker, ran aground on a reef to cause this spill of almost 11 million gallons of crude oil.
Sphincters, composed of skeletal muscles, regulate movement through our digestive and urinary systems, thus, controlling swallowing, defecation and even urination. Skeletal muscle contraction generates heat, which helps to maintain body temperature.
Two sphincters keep the contents of the stomach contained; the lower esophageal sphincter (found in the cardiac region), at the junction of the oesophagus and stomach, and the pyloric sphincter at the junction of the stomach with the duodenum.