The Endocrine system and the Nervous system work together to integrate in the brain and complement each other, but they tend to work at different speeds. Thyroid hormone regulates metabolism—the way the body uses energy— and affects nearly every organ in the body. Some endocrine diseases are common: Thyroid gland disease (occurs in >10% population in areas with iodine deficiency) Reproductive system diseases Β-cells of the pancreas – Hypothyroidism is a disorder that occurs when the thyroid gla