The endocrine system produces hormones that help regulate the body’s internal organs. Hormones are chemical messengers sent through the bloodstream and when too little or too much is produced, it is often an indication that something is wrong. In this chapter, students review what they learned in medical school about two hormones produced in the body—HCG and Insulin—and then diagnose the patients. This Teacher Guide chapter highlights the Before the Lesson, During the Lesson, and After the Lesson instructions and recommends that the teacher read prior to starting the lesson. To learn more about the Student Edition chapter referenced here, check out “Let’s Diagnose Them, Lab 6: Hormone Test.”