Four major glandular systems and their functions Endocrine System Hormone – chemical messenger produced by endocrine glands Glands-organs within a body designed to create and release chemical substance for the body to use Four major glandular systems and their functions Pituitary- (growth hormone) – “master gland” releases growth hormone and controls all other glands Thyroid- (metabolism)- responsible for regulating energy level and efficiency of metabolism Adrenal- (adrenaline)-releases chemicals used by body in response to stress or threats Gonads- (androgen & estrogen) – hormones specific to gender that affect development, reproduction and emotion