The endocrine system is a chemical messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs. In humans, the major endocrine glands are the thyroid gland and the adrenal glands. Endocrine glands release hormones into the bloodstream. It lets the hormones travel to cells in other parts of the body. The endocrine hormones help control mood, growth and development, the way our organs work, metabolism, and reproduction. The endocrine system regulates how much of each hormone is released.
The endocrine system is made up of a complex network of glands, which are organs that secrete substances. The glands of the endocrine system are where hormones are produced, stored, and released. Each gland produces one or more hormones, which go on to target specific organs and tissues in the body. The endocrine system regulates how much of each hormone is released. It can depend on levels of hormones already in the blood, or levels of other substances in the blood, like calcium. If your endocrine system isn't healthy, you might have problems developing during puberty, getting pregnant, or managing stress. You also might gain weight easily, have weak bones, or lack energy because too much sugar stays in your blood instead of moving into your cells where it's needed for energy.