(1) In addition, hormones from endocrine glands enter and leave the vascular system through regionally specialized capillaries.(2) Some are hormones, secreted by endocrine glands, and circulating in the blood, which leave through capillary walls to gain access to tissue fluids around their target cells.(3) Once a hormone is secreted, it travels from the endocrine gland through the bloodstream to the cells designed to receive its message.(4) It was first isolated from the endocrine gland in the body which has primary responsibility for holding calcium levels in your blood within a very tight range.(5) The foundations of the endocrine system are the hormones and glands.
