A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect the specific cell, tissue or organ at other location of the body.

Hormones are chemical messenger molecules that help to regulate the physiological process of the body along with the nervous system. These are released by endocrine glands in the blood. The hormones travel via the blood to reach the specific target cell, tissues and organs and show their effects to regulate certain physiological processes of the body.

For example, Luteinizing hormone is released from the anterior pituitary gland, and its target site is the Leydig cell in the ovaries and Insulin is produced in the pancreas and targets cells all around the body to uptake glucose.

Key Points

• Hormones are released from the endocrine glands into the blood, and they travel in the blood to reach the specific target cells, tissues or organs of the body to regulate the physiological processes.

Key Terms

hormone: any substance produced by one tissue and conveyed by the bloodstream to another to effect physiological activity

endocrine glands: organs in the body that secrete hormones