An much smaller than any part of a cell

leave through the cell membrane

What system have glands found throughout the body that release hormones into the bloodstream

Wjat are substances intentionally added to food to produce a desired effect?

Me d: which system contains the heart, blood, and blood vessels? a. muscular b. circulatory c. respiratory d. digestive which system contains the pituitary, adrenal, and thyroid glands? a. respiratory b. circulatory c. endocrine d. reproductive