I'm pretty sure it's fish since they evolved into both reptiles and amphibians
Explanation:
answered: Guest
can you make it bigger i can't see it
answered: Guest
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.