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.
As food progresses through the body, it moves through the different sphincters in the digestive system. In total, there are six sphincters in the digestive system, which have the general role of controlling the direction and movement of material.s food progresses through the body, it moves through the different sphincters in the digestive system. In total, there are six sphincters in the digestive system, which have the general role of controlling the direction and movement of material.