Hormone

Hormone: Biochemical Messengers

Hormones are biochemical signaling or messenger substances. They are produced in specialized cells (e.g., the thyroid or adrenal glands) to trigger specific effects or functions in the body.

A good example hormone is adrenaline, which is produced in the adrenal glands. It increases blood pressure and heart rate, among other things, and is released, for example, in stressful situations, so that energy can be quickly made available to the body.