The endocrine system is composed of glands, tissues, and organs distributed throughout the body. Endocrine glands are ductless glands that secrete hormones into the interstitial fluid. The hypothalamus is a neuroendocrine organ in the brain that regulates neural functions in addition to secreting hormones. The pituitary and pineal glands are near the hypothalamus. The thyroid and parathyroid glands are found in the neck, and the thymus is located in the upper chest region The adrenal glands are above the kidneys, and the gonads, the testes in males, ovaries in females, produce reproductive hormones. The pancreas, located near the stomach, can act as both an endocrine gland to help maintain glucose levels and an exocrine gland to help with digestion. In addition, cells in various organs and tissues, including the heart, adipose tissue, skin, and placenta, can also release endocrine signals.