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.
At the bottom of the oesophagus is a sphincter. There are several sphincters in our bodies, and they are basically tightenings, or narrowings, of a tube. Back to top. Stomach: After passing the sphincter (cardiac sphincter), food enters the stomach, a very muscular pouch.Here, digestive juices are secreted and mixed with the food. These juices are highly acidic, and therefore kill many of the germs that may enter with the food.here are several sphincters in our bodies, and they are basically tightenings, or narrowings, of a tube. Back to top. Stomach: After passing the sphincter (cardiac sphincter), food enters the stomach, a very muscular pouch.