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Biology LibreTexts

25.21: Glossary: U

  • Page ID
    17845
  • ulcerative colitis

    inflammatory bowel disease that causes ulcers (sores) in the colon and rectum

    umbilical cord

    long, narrow conduit containing two arteries and a vein that connects an embryo or fetus to the placenta

    undernutrition

    insufficient intake of nutrients, generally leading to an individual being underweight for height (in adults) or underweight for age (in children)

    universal donor

    individual with type O blood in the ABO blood group system who can donate blood to people of any ABO blood type

    universal recipient

    individual with type AB blood in the ABO blood group system who can receive a blood donation from people of any ABO blood type

    unsaturated fatty acid

    simple lipid molecule in which carbon atoms are not bonded to as many hydrogen atoms as possible because some adjacent carbon atoms in the chain share double or even triple bonds

    upper gastrointestinal (GI) tract

    part of the gastrointestinal tract that includes the mouth, pharynx, esophagus, and stomach

    urbanization

    shift in population from rural to urban areas, which is the process by which cities form and grow

    urea

    waste product of protein catabolism that is mainly filtered from blood in the kidneys and excreted in urine

    ureter

    muscular, tube-like organ of the urinary system that moves urine by peristalsis from a kidney to the bladder

    urethra

    tube-like organ of the urinary system that carries urine out of the body from the bladder and, in males, also carries semen out of the body

    uric acid

    waste product of nucleic acid catabolism that is mainly filtered from blood by the kidneys and excreted in urine

    urinary bladder

    sac-like organ that stores urine until it is excreted from the body

    urinary incontinence

    common chronic problem of uncontrolled leakage of urine

    urinary system

    organ system that includes the kidneys, ureters, urinary bladder, and urethra and that is responsible for filtering waste products and excess water from the blood and excreting them from the body in urine

    urination

    process in which urine leaves the body through the external urethral orifice

    urine

    liquid waste product of the body that is formed by the kidneys and excreted by the other organs of the urinary system

    uterine cycle

    events of the menstrual cycle that occur in the uterus, including menses and the buildup of the endometrium

    uterus (plural, uteri)

    female reproductive organ in which first an embryo and then a fetus grows and develops until birth