The endocrine system is made up of several glands that produce hormones to regulate bodily functions. The pineal gland located in the brain produces melatonin which controls sleep cycles. The hypothalamus located in the brain sends hormones that control functions like sleep, eating, and temperature. The pituitary gland is called the "master gland" as it controls other glands and regulates growth and development. Other glands include the thyroid which regulates metabolism, the pancreas which controls blood sugar, and the gonads like the ovaries and testes which produce hormones related to development and reproduction.