What roles do prokaryotes play in ecosystems?

instead of copying and pasting things off of tests or work done on computer which im sure you did, try and read over the question carefully

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.