uterus


uterus
/yooh"teuhr euhs/, n., pl. uteri /yooh"teuh ruy'/, uteruses. Anat., Zool.
the enlarged, muscular, expandable portion of the oviduct in which the fertilized ovum implants and develops or rests during prenatal development; the womb of certain mammals.
[1605-15; < L: the womb, matrix; akin to Gk hystéra womb, Skt udara belly]

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or womb

Inverted-pear-shaped organ of the female reproductive system, in which the embryo and fetus develop during pregnancy.

Lying over and behind the bladder, it is 2.5–3 in. (6–8 cm) long and about 2.5 in. (6 cm) across at the top, where the fallopian tubes enter it; at the other end, the cervix extends down into the vagina. The uterine lining (endometrium), a moist mucous membrane, changes in thickness during the menstrual cycle (see menstruation), being thickest at ovulation in readiness for a fertilized egg. The uterine wall, about 1 in. (2.5 cm) thick, expands and becomes thinner as a fetus develops inside. The cervix expands to about 4 in. (10 cm) for delivery. Disorders of the uterus include infections, benign and malignant tumours, prolapse, endometriosis, and fibroids (leiomyomas; see muscle tumour).

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also called  Womb,  

      an inverted pear-shaped muscular organ of the female reproductive system, located between the bladder and rectum. It functions to nourish and house the fertilized egg until the unborn child, or offspring, is ready to be delivered.

      The uterus has four major regions: the fundus is the broad, curved upper area in which the fallopian tubes (q.v.) connect to the uterus; the body, the main part of the uterus, starts directly below the level of the fallopian tubes and continues downward until the uterine walls and cavity begin to narrow; the isthmus is the lower, narrow neck region; the lowest section, the cervix, extends downward from the isthmus until it opens into the vagina. The uterus is 6 to 8 centimetres (2.4 to 3.1 inches) long; its wall thickness is approximately 2 to 3 centimetres (0.8 to 1.2 inches). The width of the organ varies; it is generally about six centimetres wide at the fundus and only half this distance at the isthmus. The uterine cavity opens into the vaginal cavity, and the two make up what is commonly known as the birth canal.

      Lining the uterine cavity is a moist mucous membrane known as the endometrium. The lining changes in thickness during the menstrual cycle, being thickest during the period of egg release from the ovaries (see ovulation). If the egg is fertilized, it attaches to the thick endometrial wall of the uterus and begins developing. If the egg is unfertilized, the endometrial wall sheds its outer layer of cells; the egg and excess tissue are then passed from the body during menstrual bleeding (see menstruation). The endometrium also produces secretions that help keep both the egg and the sperm cells alive. The components of the endometrial fluid include water, iron, potassium, sodium, chloride, glucose (a sugar), and proteins. Glucose is a nutrient to the reproductive cells, while proteins aid with implantation (q.v.) of the fertilized egg. The other constituents provide a suitable environment for the egg and sperm cells.

      The uterine wall is made up of three layers of muscle tissue. The muscle fibres run longitudinally, circularly, and obliquely, entwined between connective tissue of blood vessels, elastic fibres, and collagen fibres. This strong muscle wall expands and becomes thinner as a child develops inside the uterus. After birth, the expanded uterus returns to its normal size in about six to eight weeks; its dimensions, however, are about one centimetre (0.4 inch) larger in all directions than before childbearing. The uterus is also slightly heavier and the uterine cavity remains larger.

      The uterus of a female child is small until puberty, when it rapidly grows to its adult size and shape. After menopause, when the female is no longer capable of having children, the uterus becomes smaller, more fibrous, and paler. Some afflictions that may affect the uterus include infections; benign and malignant tumours; malformations, such as a double uterus; and prolapse, in which part of the uterus becomes displaced and protrudes from the vaginal opening.

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Universalium. 2010.

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  • utérus — [ yterys ] n. m. • 1560; lat. uterus ♦ Organe situé dans la cavité pelvienne de la femme, entre la vessie et le rectum, destiné à contenir l œuf fécondé jusqu à son complet développement. ⇒ matrice. Corps, col de l utérus. Radio du col de l… …   Encyclopédie Universelle

  • Uterus — Utérus L’utérus, ou matrice, est un organe participant aux fonctions reproductrices chez les mammifères dont la femme. C est une poche dont l intérieur très vascularisé, ouverte vers le col utérin à l extérieur, et qui du coté postérieur, vers l… …   Wikipédia en Français

  • Uterus — U te*rus, n. [L.] 1. (Anat.) The organ of a female mammal in which the young are developed previous to birth; the womb. [1913 Webster] Note: The uterus is simply an enlargement of the oviduct, and in the lower mammals there is one on each side,… …   The Collaborative International Dictionary of English

  • uterus — 1610s, from L. uterus womb, belly (pl. uteri), from PIE root *udero abdomen, womb, stomach (Cf. Skt. udaram belly, Gk. hystera womb, Lith. vederas stomach, O.C.S. vedro bucket ) …   Etymology dictionary

  • Utĕrus — (lat.), die Gebärmutter, s.u. Genitalien B). U. oblīquus, s. Gebärmutterbeugung. Uterussystem (Uterinsystem), der ganze Apparat der weiblichen Geschlechtstheile, s.u. Genitalien B). Uteri procidentĭa (U. prolapsus), Gebärmuttervorfall …   Pierer's Universal-Lexikon

  • Utĕrus — (lat.), Gebärmutter; männlicher U., s. Vesicula prostatica und Vorsteherdrüse. Uterussonde, ein gekrümmtes Metallstäbchen zur Untersuchung der Lageveränderungen der Gebärmutter und der Großenverhältnisse ihrer Höhle …   Meyers Großes Konversations-Lexikon

  • Uterus — Utĕrus (lat.), die Gebärmutter (s.d.) …   Kleines Konversations-Lexikon

  • Uterus — Uterus, lat., Gebärmutter, Fruchthalter, das weibliche Geschlechtsorgan, in welchem das befruchtete Ei zum Fötus ausgebildet wird. Er ist ein platter, flaschenförmiger, muskulöser hohler Körper, zwischen der Harnblase und dem Mastdarm gelegen.… …   Herders Conversations-Lexikon

  • Uterus — Uterus, Gebärmutter, der Weiterentwicklung der befruchteten Eier dienender Abschnitt der f Geschlechtsorgane, in dem bei viviparen Tieren der Embryo ernährt wird. Bei Wirbellosen kann die Vagina (z.B. Tsetsefliegen) oder der Eileiter (z.B.… …   Deutsch wörterbuch der biologie

  • ùterus — m anat. unutarnji spolni organ žene u kojem se razvija plod; maternica, materica, plodnica ✧ {{001f}}lat …   Veliki rječnik hrvatskoga jezika

  • uterus — ùterus m DEFINICIJA anat. unutarnji spolni organ žene u kojem se razvija plod; maternica, materica ETIMOLOGIJA lat …   Hrvatski jezični portal


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