duct that transmits urine from the bladder to the exterior of the body during urination. The urethra is held closed by the urethral sphincter, a muscular structure that helps keep urine in the bladder until voiding can occur.
in male placental mammals, any of the glands that branch off the internal wall of the urethra, the passageway for both urine and semen. The glands contribute mucus to the seminal fluid. They are located along the whole length of ...
infection and inflammation of the urethra, the channel for passage of urine from the urinary bladder to the outside. Urethritis is more frequent in males than in females. Its causes vary with age, sexual practices, and hygienic standards. Urethritis due ...
park in northeastern North Island, New Zealand. Established in 1954, it has an area of 821 square miles (2,127 square km) and has the largest expanse of indigenous forest in the North Island. The park is located in a region ...
American scientist awarded the Nobel Prize for Chemistry in 1934 for his discovery of the heavy form of hydrogen known as deuterium. He was a key figure in the development of the atomic bomb and made fundamental contributions to a ...
uranium mine and village, Viseu distrito ("district"), north-central Portugal. It lies south of Viseu town near the Mondego River. Although the deposits are small, the uranium extracted there in the late 1970s and early '80s was nevertheless significant enough to ...
city, south-central Uzbekistan. The city lies along the Shavat Canal and the Amu Darya (river). Urgench was founded when the inhabitants of the ancient city of Urgench, near present-day Kunya-Urgench, 80 miles (130 km) to the northwest, moved there in ...
a people of the northwestern part of the Niger River delta in extreme southern Nigeria. They speak a language of the Kwa branch of the Niger-Congo language family. The term Sobo is used by ethnographers as a cover term for ...
canton, central Switzerland, traversed by the steep-sided valleys of the Reuss River and its tributaries. About one-half of the canton's area is reckoned as productive. Forests occupy part of the canton, and more than 20 percent of the unproductive area ...
Argentine soldier and statesman who led the military coup that in September 1930 overthrew the liberal regime of President Hipolito Irigoyen and restored the old landed oligarchy to the political power it had lost after the revolution of 1916. German ...
a compound belonging to the purine group, and the chief form in which nitrogen, resulting from the breakdown of protein during digestion, is excreted by reptiles and birds. Small quantities of uric acid (about 0.7 gram per day) are excreted ...
in the Apocrypha, a leading angel, sometimes ranked as an archangel with Michael, Gabriel, and Raphael. Because his name in Hebrew means "fire of God," or "light of God," he has been variously identified in Jewish traditions as an angel ...
laboratory examination of a sample of urine to obtain clinical information. Most of the substances normally excreted in the urine are metabolic products dissolved or suspended in water. A deviation from normal in the concentration of urinary constituents or the ...
in most vertebrates, except birds, organ for the temporary storage of urine from the kidneys, connected to the kidneys by means of tubular structures called ureters. A urinary bladder is present in fish as an expansible part of the urinary ...
blockage or constriction of the excretory ducts, causing urine to be dammed up in the kidneys (hydronephrosis). Obstructions in the urinary tract cause distension of the walls of the bladder, ureter, or renal pelvis, depending on the location of the ...
the process of excreting urine from the urinary bladder. Nerve centres for the control of urination are located in the spinal cord, the brainstem, and the cerebral cortex (the outer substance of the large upper portion of the brain). Both ...
liquid or semisolid solution of metabolic wastes and certain other, often toxic, substances that the excretory organs withdraw from the circulatory fluids and expel from the body. The composition of urine tends to mirror the water needs of the organism. ...
American novelist known for panoramic, action-filled works such as the World War II novel Battle Cry (1953) and Exodus (1958), which deals with the struggle to establish and defend the state of Israel.
lake in northwestern Iran that is the largest lake in the Middle East. It covers an area that varies from 2,000 to 2,300 square miles (5,200 to 6,000 square km). Like the Dead Sea, it is remarkable for the extreme ...
any plant of the genus Physcomitrium (order Bryales), characterized by urn-shaped or top-shaped capsules (spore cases) with lobed, hoodlike coverings. Fewer than 10 species are native to North America. The most common is P. turbinatum, sometimes called top moss, about ...
a Late Bronze Age culture of Europe, so called because of the custom of placing the cremated bones of the dead in urns. The Urnfield culture first appeared in east-central Europe and northern Italy; from the 12th century BC onward, ...
any defect in the organs and tissues responsible for the formation and excretion of urine or in the sex organs or in both. Some of the more important conditions include:
in vertebrates, the organs concerned with reproduction and urinary excretion. Although their functions are unrelated, the structures involved in excretion and reproduction are morphologically associated and often use common ducts. The major structures of the urinary system in mammals are ...
X-ray examination of any part of the urinary tract after introduction of a radiopaque substance (often an organic iodine derivative) that casts an X-ray shadow. This contrast fluid, which passes quickly into the urine, may be taken orally or injected ...
medical specialty involving the diagnosis and treatment of diseases and disorders of the urinary tract and of the male reproductive organs. (The urinary tract consists of the kidneys, the bladder, the ureters, and the urethra.)
author of one of the most original and vivid translations from any foreign language into English. His works are marked by eccentricity of both language and method.
in astronomy, a constellation of the Northern Hemisphere, at about 10 hours 40 minutes right ascension (the coordinate on the celestial sphere analogous to longitude on the Earth) and 56° north declination (angular distance north of the celestial equator). It ...
in astronomy, a constellation of the northern sky, seven of whose stars outline the Little Dipper. Polaris (Alpha Ursae Minoris), at the end of the Little Dipper's handle, marks (roughly) the position of the north celestial pole. The constellation lies ...
(princess of the) French noblewoman who exercised great influence in the government of Spain between 1701 and 1714, during the period of the War of the Spanish Succession.
legendary leader of 11 or 11,000 virgins reputedly martyred at Cologne, now in Germany, by the Huns, 4th-century nomadic invaders of southeastern Europe. The story is based on a 4th- or 5th-century inscription from St. Ursula's Church, Cologne, stating that ...
a Roman Catholic religious order of women founded at Brescia, Italy, in 1535, by St. Angela Merici, as the first institute for women dedicated exclusively to the education of girls. Angela and her 28 companions placed themselves under the protection ...
the nettle family comprising about 45 genera of herbs, shrubs, small trees, and a few vines, distributed primarily in tropical regions. The family is typical of the nettle order (Urticales). Many species, especially the nettles (Urtica; see ) and Australian ...
nettle order of dicotyledonous flowering plants, the largest order in the subclass Hamamelidae. The order includes a diversity of plant types that range from small herbaceous species to large trees. Among the members are stinging nettles; mulberry, fig, and elm ...
city, west-central Michoacan estado ("state"), west-central Mexico. Founded in 1533, Uruapan (from a Tarascan Indian term meaning "where the flowers abound") is famous for its Spanish-colonial atmosphere and colourful lacquerware and Indian handicrafts (see ). It is a rail terminus ...
river in the Amazon drainage system, rising in the Andes of southern Peru, near the border between Cuzco and Puno departamentos. It flows for about 450 miles (725 km) to its junction with the Apurimac, where it forms the Ucayali. ...
city, western Rio Grande do Sul estado (state), southern Brazil. It lies along the Uruguay River, across the bridge from the town of Paso de los Libres, Argentina. Founded in 1839 as Sant' Ana do Uruguai, Uruguaiana ...
country located on the southeastern coast of South America. The second smallest nation on the continent, Uruguay has long been overshadowed politically and economically by the adjacent republics of Brazil and Argentina, with both of which it shares many cultural ...
river in southern South America that rises in the coastal range of southern Brazil. Its chief headstream, the Pelotas River, rises just 40 miles (64 km) from the Atlantic coast at Alto do Bispo in Santa Catarina state, Brazil, and ...
city in the Uighur Autonomous Region of Sinkiang, northwestern China. Urumchi (Mongolian: "Fine Pasture") is the capital of the autonomous region. Situated in a fertile belt of oases along the northern face of the T'ien Shan (mountains), the city commands ...
city, Oita ken (prefecture), northern Kyushu, Japan; it lies 24 miles (39 km) northwest of the prefectural capital Oita. The city developed around the site of the first and most famous of shrines dedicated to the Shinto god Hachiman, Usa ...
holding company for the American airline incorporated on March 5, 1937, as All American Aviation, Inc.; the airline was renamed All American Airways, Inc., in 1948, Allegheny Airlines, Inc., in 1953, and USAir, Inc., in 1979. The holding company was ...
city in the interior of western Turkey, at an elevation of 2,976 feet (907 m) above sea level. Situated in a region that was once part of the Hittite empire, Usak lies near the ruins of ancient Flaviopolis. In more ...
in medieval English property law, the right of one person to take the profits of land belonging to another. It involved at least two and usually three persons. One man (A) would convey or enfeoff land to another (B) on ...
