ulcerative colitis - (ul-sur-a-tiv cO-lI-tis) - A chronic disease of unknown cause characterized by ulceration of the colon and rectum, with rectal bleeding, abdominal pain, and diarrhea; frequently causes anemia and electrolyte imbalance, and is less frequently complicated by peritonitis inflammation of the abdominal membrane, toxic megacolon (a condition of extreme dilation and hypertrophy of the colon), or cancer of the colon.

ulcers (of the skin) - An open sore or irritation on the skin. -

ulcers (of the stomach) - A sore or erosion in the lining of the stomach. -

ultrasonography - (ul-tra-so-nog-ru-fE) - The location, measurement, or delineation of deep structures by measuring the reflection or transmission of high frequency or ultrasonic waves. Computer calculation of the distance to the sound-reflecting or absorbing surface plus the known orientation of the sound beam gives a two- or three-dimensional image.-

ultrasound, diagnostic - (ul-tra-sownd) - Ultrasound imaging, also known as ultrasound scanning or sonography, is a method of obtaining images from inside the human body through the use of high frequency sound waves. The soundwaves' echoes are recorded and displayed as a real-time, visual image. No ionizing radiation is involved in ultrasound imaging. -

ultraviolet - (ul-tra-vI-O-let) - Denoting electromagnetic rays at higher frequency than the violet end of the visible spectrum. -

undescended testicle - A testicle that hasn't descended from the body. -

uranium (U) - (yU-rA-nEum) - A radioactive metallic element, atomic no. 92, atomic wt. 238.0289, occurring mainly in pitchblende and notable for its two isotopes: 238U and 235U (99.2745% and 0.720%, respectively, the rest being made up by 234U), 235U being the first substance ever shown capable of supporting a self-sustaining chain reaction. -

ureter - (yU-rE-ter) - The tube that carries urine from each kidney to empty into the bladder.

urethra - A tube that carries urine from the bladder out of the body. In men, the urethra carries semen from the prostate and other sex glands out of the body through the penis. -

urethrocystometry - (yU-rE-thrO-sis-tom-a-trE) - A procedure that simultaneously measures pressures in urinary bladder and urethra.

uric acid - A waste product left over from normal chemical processes in the body and found in the urine and blood. -

urinary - Relating to the organs involved in producing and passing urine. -

urography - (yU-rog-ru-fE) - Radiography of any part (kidneys, ureters, or bladder) of the urinary tract. -

urologist - A specialist in the diagnosis and treatment of genitourinary tract diseases. -

uterine - (yU-terin) - Relating to the uterus.

uterine cavity - The space within the uterus. -

uterine fibroid embolization - A minimally invasive treatment for fibroid tumors of the uterus, , in which a synthetic material called an embolic agent is placed inside one or more of the blood vessels that supply the tumors with blood. As the vessels close off, the fibroid tissue shrinks. See the Uterine Fibroid Embolization (UFE) page for more information. -

uterus - (yU-terus) - The hollow muscular organ in which the impregnated ovum (egg) is developed into the child; it is about 7.5 cm in length in the nonpregnant woman, and consists of a main portion (body) with an elongated lower part (neck), at the extremity of which is the opening (os). The upper rounded portion of the uterus, opposite the os, is the fundus, at each extremity of which is the horn marking the part where the uterine tube joins the uterus and through which the ovum reaches the uterine cavity after leaving the ovary. The organ is supported in the pelvic cavity by the broad ligaments, round ligaments, cardinal ligaments, and rectouterine (relating to rectum and uterus) and vesicouterine (relating to bladder and uterus) folds or ligaments.