Category: U

  • Unipennate muscle

    A muscle whose fibers converge on only one side of a tendon.  

  • Uterine activity monitor

    An electronic sensor applied to or worn around the abdomen to note and record uterine contractions and fetal heart tones.  

  • Unit monitor

    In radiation therapy, a calibrated unit of dose that determines the length of the treatment.  

  • Ultraviolet microscope

    A microscope using ultraviolet radiations as a light source and having an optical system for transmitting them. Used in observing specimens that fluoresce, such as tissues stained with a fluorescent dye.  

  • Unit membrane

    The phospholipid bilayer first described as the typical cell membrane, then as the membrane of intracellular structures.  

  • Umbilicopubic line

    The portion of median line extending from the umbilicus to the symphysis pubis.  

  • Uterorectosacral ligament

    One of the ligaments that arise from the sides of the cervix and pass upward and backward, passing around the rectum, to the second sacral vertebra. They are enclosed within the rectouterine folds, which demarcate the borders of the rectouterine pouch.  

  • Uterine leiomyoma

    A benign tumor of the uterus of smooth muscle origin. Also called myoma, fibroid, or fibromyoma, it is the most common tumor of the female reproductive tract.  

  • Ulnomeniscal-triquetral joint

    The functional articulation of the distal ulna, articular disk, and triquetrum. The disk may subluxate following injury or with arthritis and block supination of the forearm.  

  • Uterine inversion

    A condition that may occur during the third stage of labor in which a relaxed uterus is turned inside out, causing the internal surface to protrude into the vagina. Uterine inversion most commonly is caused by traction on an umbilical cord attached to a yet-adherent placenta or to application of forceful fundal pressure to empty…