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estrogen

(Encyclopedia)CE5 estrogen ĕsˈtrəjən [key], any one of a group of hormones synthesized by the reproductive organs and adrenal glands in females and, in lesser quantities, in males. The estrogens cause the th...

hypersensitivity

(Encyclopedia)hypersensitivity, heightened response in a body tissue to an antigen or foreign substance. The body normally responds to an antigen by producing specific antibodies against it. The antibodies impart i...

hair

(Encyclopedia)CE5 A. Cross section of a hair shaft B. General structure of a hair hair, slender threadlike outgrowth from the skin of mammals. In some animals hair grows in dense profusion and is called fur or ...

nicotine

(Encyclopedia)nicotine, C10H14N2, poisonous, pale yellow, oily liquid alkaloid with a pungent odor and an acrid taste. It turns brown on exposure to air. Nicotine, a naturally occurring constituent of tobacco, is t...

Lessing, Doris

(Encyclopedia)Lessing, Doris, 1919–2013, British novelist, b. Kermanshah, Persia (now Iran) as Doris May Tayler. Largely self-educated, she was brought up on a farm in Southern Rhodesia (now Zimbabwe), and in 194...

Wilder, Thornton Niven

(Encyclopedia)Wilder, Thornton Niven, 1897–1975, American playwright and novelist, b. Madison, Wis., grad. Yale (B.A., 1920), Princeton (M.A., 1925). He received most of his early education in China, where his fa...

wings

(Encyclopedia)CE5 A. Structure of a bird wing B. Structure of a bat wing wings, flight organs of the bird, the bat, and the insect. Birds' wings are pectoral appendages that are basically the same in skeletal...

bromine

(Encyclopedia)bromine brōˈmēn, –mĭn [key] [Gr.,=stench], volatile, liquid chemical element; symbol Br; at. no. 35; at. wt. 79.904; m.p. –7.2℃; b.p. 58.78℃; sp. gr. of liquid 3.12 at 20℃; density of va...

radiation sickness

(Encyclopedia)radiation sickness, harmful effect produced on body tissues by exposure to radioactive substances. The biological action of radiation is not fully understood, but it is believed that a disturbance in ...

steroids

(Encyclopedia)CE5 Two examples of steroids steroids, class of lipids having a particular molecular ring structure called the cyclopentanoperhydro-phenanthrene ring system. Steroids differ from one another in th...