Hormone meaning

The definition of a hormone is a substance formed in an organ or tissue in the body of a plant or animal and then transported by body fluid to another organ or tissue for a specific action.

A substance formed in some organ of the body, as the adrenal glands, the pituitary, etc., and carried by a bodily fluid to another organ or tissue, where it has a specific effect.

Any of various similar substances found in plants and insects that regulate development.

A similar substance produced in a plant, as an auxin.

A synthetic substance produced to have similar effects to an animal or plant hormone.

The human sex hormones as they affect mood, personality, etc.

Any of various similar substances found in plants and invertebrates that regulate development.

A chemical substance secreted by an endocrine gland or group of endocrine cells that acts to control or regulate specific physiological processes, including growth, metabolism, and reproduction. Most hormones are secreted by endocrine cells in one part of the body and then transported by the blood to their target site of action in another part, though some hormones act only in the region in which they are secreted. Many of the principal hormones of vertebrates, such as growth hormone and thyrotropin, are secreted by the pituitary gland, which is in turn regulated by neurohormone secretions of the hypothalamus. Hormones also include the endorphins, androgens, and estrogens.

A substance that is synthesized by a plant part and acts to control or regulate the growth and development of the plant. The action and effectiveness of a hormone can depend on the hormone's chemical structure, its amount in relation to other hormones that have competing or opposing effects, and the ways in which it interacts with chemical receptors in various plant parts. Auxins, cytokinins, gibberellins, abscisic acid, and ethylene are plant hormones.