Hormones

[hawr-mohn] /ˈhɔr moʊn/

noun
1.
Biochemistry. any of various internally secreted compounds, as insulin or thyroxine, formed in endocrine glands, that affect the functions of specifically receptive organs or tissues when transported to them by the body fluids.
2.
Pharmacology. a synthetic substance used in medicine to act like such a compound when introduced into the body.
3.
Botany.. Also called phytohormone. any of various plant compounds, as auxin or gibberellin, that control growth and differentiation of plant tissue.
/ˈhɔːməʊn/
noun
1.
a chemical substance produced in an endocrine gland and transported in the blood to a certain tissue, on which it exerts a specific effect
2.
an organic compound produced by a plant that is essential for growth
3.
any synthetic substance having the same effects
n.

1905, from Greek hormon “that which sets in motion,” present participle of horman “impel, urge on,” from horme “onset, impulse,” from PIE *or-sma-, from root *er- “to move, set in motion.” Used by Hippocrates to denote a vital principle; modern meaning coined by English physiologist Ernest Henry Starling (1866-1927). Jung used horme (1915) in reference to hypothetical mental energy that drives unconscious activities and instincts. Related: Hormones.

hormone hor·mone (hôr’mōn’)
n.
A substance, usually a peptide or steroid, produced by one tissue and conveyed by the bloodstream to another to effect physiological activity, such as growth or metabolism.
hor·mon’al (-mō’nəl) adj.
hormone
(hôr’mōn’)

Our Living Language : Among the most abundant and influential chemicals in the human body are the hormones, found also throughout the entire animal and plant kingdoms. The endocrine glands alone, including the thyroid, pancreas, adrenals, ovaries, and testes, release more than 20 hormones that travel through the bloodstream before arriving at their targeted sites. The pea-sized pituitary gland, located at the base of the brain below the hypothalamus, is considered the most crucial part of the endocrine system, producing growth hormone and hormones that control other endocrine glands. Specialized cells of the nervous system also produce hormones. The brain itself releases endorphins, hormones that act as natural painkillers. Hormones impact almost every cell and organ of the human body, regulating mood, growth, tissue function, metabolism, and sexual and reproductive function. Compared to the nervous system, the endocrine system regulates slower processes such as metabolism and cell growth, while the nervous system controls more immediate functions, such as breathing and movement. The action of hormones is a delicate balancing act, which can be affected by stress, infection, or changes in fluids and minerals in the blood. The pituitary hormones are influenced by a variety of factors, including emotions and fluctuations in light and temperature. When hormone levels become abnormal, disease can result, such as diabetes from insufficient insulin or osteoporosis in women from decreased estrogen. On the other hand, excessive levels of growth hormone may cause uncontrolled development. Treatment for hormonal disorders usually involves glandular surgery or substitution by synthetic hormones.

Chemical substances, produced in the body by endocrine glands, that are transported by the blood to other organs to stimulate their function. Adrenaline, estrogen, insulin, and testosterone are all hormones.