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 [u´ter-us] (pl. u´teri) (L.)
the hollow muscular organ in female mammals in which the zygote (fertilized ovum) normally becomes embedded and in which the developing embryo and fetus is nourished; in humans it is normally about the size and shape of a pear. Called also metra and womb.

The upper part of the uterus, or fundus uteri, is broad and flattened; the middle part (body), or corpus uteri, is large and open; and the lower part, or cervix uteri, is narrow and tubular and opens downward into the vagina. Two fallopian tubes enter the uterus at the upper end, one on each side. The walls of the uterus are composed of muscle, and its lining is mucous membrane. The muscular substance of the uterus is called the myometrium, and the inner lining is called the endometrium. Between puberty and menopause, the lining goes through a monthly cycle of growth and discharge, known as the menstrual cycle. menstruation is the time in the cycle when the tissue prepared by the uterus for a possible embryo or fertilized egg is unused and passes out through the vagina.

The menstrual cycle is interrupted by pregnancy when a mature ovum is fertilized by a spermatozoon. Fertilization usually takes place in the fallopian tube; the fertilized ovum continues moving along the tube and comes to rest in the uterus, where it implants in the endometrium. The endometrium then serves to anchor the placenta, which filters nutrients from the mother's blood into the blood of the growing fetus. (See also reproduction and female reproductive organs.)
Disorders of the Uterus. The main organs of the female reproductive system, the uterus, fallopian tubes, and ovaries, are connected to each other by ligaments that normally hold each in its proper place. Occasionally childbirth causes displacement of the uterus. The ligaments may stretch and weaken enough to permit the uterus to bulge into the vagina. This is called a prolapsed uterus. The uterus is also subject to cancer as well as to benign growths in the uterine wall, called leiomyomas.
Uterus and uterine tubes. From Applegate, 2000.
uterus didel´phys the existence of two distinct uteri in the same individual; called also didelphia and uterus duplex.
duplex uterus (uterus du´plex) uterus didelphys.




the condition of having a double uterus.