What best describes when our scientific body of knowledge was developed

it is built on years and years of scientists figuring things out, countless expirments, inventions. etc.

hope this helps.

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.