sentence2_structure: The endocrine system<>produces<>most of the hormones$$$the hormones<>regulate<>body functions
sentence1: It is the endocrine glands that produce hormones that regulate the body's growth, metabolism, autonomic system and sexual development and function.
sentence2: The endocrine system produces most of the hormones that regulate body functions.
question: Which human organ system produces most of the hormones that regulate body functions?