Does any digestion of food occur in the esophagus?

no. the mouth secretes ptyalin converting starches to maltose

geologic time scale (for gradpoint) =)

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.