Hormone A chemical substance produced in one part of the body that is released into the blood to control functions of another part or parts of the body. Examples include insulin, estrogen, and adrenaline/epinephrine. Related Articles: Episode 30: PrediabetesAsk the Pediatric EndocrinologistEpisode 23: Diabetes & the Prevention of Kidney DiseaseEpisode 12: Medications for Type 2 DiabetesEpisode 31: Diabetes and Sleep