sentence2_structure: The endocrine system<>produces<>most of the hormones$$$the hormones<>regulate<>body functions
sentence1: The endocrine system is a complex network of glands and hormones that regulates many of the body's functions, including growth, development and maturation, as well as the way various organs operate.
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?