Summary. The thymus gland acts to regulate the immune system through the development of immune cells responsible for cell mediated immunity. In addition to immune function, the thymus also produces hormones that promote growth and maturation.Thymic hormones influence structures of the endocrine system, including the pituitary gland and adrenal glands, to assist in growth and sexual development.The thymus and its hormones also influence other organs and organ systems including the kidneys, spleen, reproductive system, and central nervous system.hymic hormones influence structures of the endocrine system, including the pituitary gland and adrenal glands, to assist in growth and sexual development. The thymus and its hormones also influence other organs and organ systems including the kidneys, spleen, reproductive system, and central nervous system.