Endocrine system is a group of glands that secretes particular substances (termed as hormones) directly to the bloodstream that has specific functions for growth, protection and metabolism.
Endocrine glands are called ductless, which means that they secrete hormones directly into the blood stream as contrary to the exocrine glands that uses ducts to transport molecules.
A hormone that is secreted by particular endocrine glands is a biomolecule that communicates and travels in the body until it reaches the target organs/cells to which it can react. As the hormone reaches the area of the target organs or cells, it attaches itself to the receptor of the receiving organs or cells that produces signal of a particular function.
In order to make a better illustration, here is a specific endocrine organ and their function/s. Adrenal glands are located on top of the two kidneys that secrete the very famous adrenaline. Adrenaline, also called Epinephrine has many specific functions such as: increasing of oxygen and glucose supply in the brain; increase in heart rate, induces breakdown of lipids and fats, dilates the pupil. That’s where the famous phrase “adrenaline rush” is created.
Endocrine system contains a group of glands whose main task is to release chemical messengers in the bloodstream throughout the body to specific organs or tissues telling them to carry on with their functions when a cell is affected. The chemical messengers that carry the message are known as hormones.
The endocrine system is a group of glands that release hormones. The endocrine system works by releasing hormones straight into the bloodstream.
The endocrine system is a group of glands that release/secrete hormones. The endocrine system works by releasing hormones straight into the bloodstream unlike their exocrine counterparts which release hormones into ducts.
The various physiological activities of the body are controlled by two systems: nervous and endocrine. In man, as in all other mammals, the endocrine system consists of about ten different glands located in particular parts of the body. Theses gland have no ducts and liberate their secretions, known as the hormones, directly into the bloodstream. For this reason the endocrine glands are also referred to as the ductless glands.
A hormone may be defined as a specific product ( organic substance) of an endocrine gland secreted into the blood which carries it to some part of the body where it produces a definite physiological effect. This effect may be either excitatory or inhibitory in its action. Thus, hormones are not only the"chemical messengers" that pass from the glands via the bloodstream to the target organ or some process; but they are important regulating substances that control virtually every aspect of the metabolism in living cells.