Endocrine Glands and Hormones
The endocrine system is made up of the endocrine glands that release hormones. Although there are eight major endocrine glands are Pituitary, Thyroid, Adrenal, Testis, Pineal, Thymus, Pancreas, Ovary) sprinkled throughout the body, they are still considered to be one system because they have similar functions, similar mechanisms of influence, and many important interrelationships.
Some glands also have non-endocrine regions that have functions other than hormone release. As like, the pancreas has a major exocrine portion that secretes digestive enzymes and endocrine portion that secretes hormones. The ovaries and testes secrete hormones and also produce the ova and sperm. Some organs, like stomach, intestines, and heart, produce hormones, but their primary function is not hormone secretion.