What is the definition for endoplasmic reticulum

It is a structure that englobes the nucleus and helps in the synthesis of lipids and in the transport of proteins throught the cell.

→ The image below shows you an endoplasmatic reticulum, both smooth and rough ones.

Hope it helped,

BioTeacher101

what? are the statements?

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.