| ULNA: |
Larger of the two bones in the forearm. |
| ULTRASOUND: |
A diagnostic procedure that projects high-frequency sound waves into
the body and changes the echoes into pictures (sonograms) shown on a monitor.
Different types of tissue reflect sound waves differently. This makes it
possible to find abnormal growths. |
| ULTRAVIOLET RADIATION: |
Invisible rays that are part of the energy that comes from the sun.
Ultraviolet radiation can burn the skin and cause skin cancer. It is made
up of two types of rays, UVA and UVB. UVB rays are more likely than UVA
rays to cause sunburn, but UVA rays pass further into the skin. Scientists
have long thought that UVB radiation can cause melamona and other types
of skin cancer. They now think that UVA radiation also may add to skin
damage that can lead to cancer. For this reason, skin specialists recommend
that people use sunscreens that block both kinds of radiation. |
| UMBILICAL ARTERY: |
One of (normally) two high-pressure, narrow-calibre, blood vessels
carrying oxygen-poor blood from the fetus to the placenta, and accompanying
a single umbilical vein. |
| UMBILICAL CORD: |
The fibrous cord-like structure containing two arteries and a vein
and connecting the fetus to the placenta. Oxygen and nutrients from the
mother's circulation pass through the umbilical cord to the fetus. |
| UMBILICAL HERNIA: |
A bulge caused by stretched tissue around the umbilicus. |
| UMBILICUS: |
The scar formed at the site of attachment of the umbilical cord to
the fetus; the navel. |
| UNDESCENDED TESTICLE: |
Failure of a testicle to enter the scrotum. |
| UNILATERAL: |
Involving one side only. |
| UNPROVEN METHODS: |
Treatments that use substances
or methods of treating disease that
have not been shown effective by accepted scientific methods. |
| URETERS: |
Long tubes, one leading from each kidney, which convey the urine to
the bladder. |
| URETHRA: |
Hollow tube through which urine (and semen in men) is transported from
the bladder to outside the body. |
| URETHRAL STENOSIS: |
Narrowing of the anatomical tube which drains the urinary bladder. |
| URINATION: |
Act of voiding urine. |
| URINE: |
Fluid waste produced in the kidneys, stored in the bladder, and released
through the urethra. |
| UROLOGICAL: |
Concerned with the urinary system. |
| UTERUS: |
Often called the womb, this is the organ in which a fetus develops.
During pregnancy, the uterus expands. But when a woman is not pregnant,
the uterus is small, hollow, and shaped like a flattened pear. |
| UVEA: |
Layer of the eye beneath the sclera, consisting of the iris, ciliary
body and choroid. The visible pigments in the eye are seen in the uvea. |
| UVULA: |
The prominent anatomic structure dangling downward visibly at the back
of the mouth (pharynx). |
