<Table> <Tr> <Td> </Td> <Td> Look up sphincter in Wiktionary, the free dictionary . </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> Look up sphincter in Wiktionary, the free dictionary . </Td> </Tr> <P> A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning . Sphincters are found in many animals . There are over 60 types in the human body, some microscopically small, in particular the millions of precapillary sphincters . Sphincters relax at death, often releasing fluids . </P> <P> Sphincters control the passage of liquids and solids . This is evident, for example, in the blowholes of numerous marine mammals . </P>

How many sphincter muscles are in the body