The endocrine system is a collection of glands that secrete chemical messages we call hormones These signals are passed through the blood to arrive at a target organ, which has cells possessing the appropriate receptor Exocrine glands (not part of the endocrine system) secrete products that are passed outside the bodyHealthcare, medicine endocrine system stock pictures, royaltyfree photos & images Endocrine Glands Image Human anatomy icons set Endocrine system pituitary gland, pineal gland, testicle, ovary, pancreas, thyroid, thymus, adrenal gland Vector illustration isolated on a dark grey background endocrine system stock illustrations Exocrine glands release their secretions onto an epithelial surface via a duct Exocrine glands consist of two main parts, Adenocarcinomas are malignant tumours that arise from glandular epithelium and are common in the gastrointestinal system, uterus, lungs, breast and prostate They consist of abnormal glands and can secrete mucus Exocrine Glands