Category: U

The protrusion of any portion of the uvea through the sclera.  

A sphincter that keeps the opening between the posterior pharynx and the proximal esophagus closed, except during swallowing. It is maintained principally by the cricopharyngeal muscle.  

A device suitable for use in exploring the urethra.  

One of the slanting venous channels from the placenta serving to convey the maternal blood from the intervillous lacunae back into the uterine veins.  

One of the venous channels in the walls of the uterus during pregnancy.  

Radiographical and fluoroscopic examinations of the stomach and duodenum after the ingestion of a contrast medium, such as barium sulfate or an iodinized glucose solution.  

One of the two functional divisions of the uterine musculature during labor. During labor the upper uterine segment forcibly contracts, becoming progressively shorter and thicker, exerting traction on the more passive lower segment, and increasing the hydrostatic pressure against the cervix. The combination of forces and traction gradually cause the lower segment to thin, resulting…

Substances present in urine (i.e., bacteria, mucus, phosphates, uric acid, calcium oxalate, calcium carbonate, calcium phosphate, magnesium and ammonium phosphate; and more rarely, cystine, tyrosine, xanthine, hippuric acid, hematoidin) that separate and accumulate at the bottom of a container of urine. This process may be accelerated by centrifuging the urine specimen.  

The cutting of sections extraordinarily thin (less than 1 μm thick), especially for use in electron microscopy.  

A public health effort to identify infants born with impaired hearing at the earliest possible age (e.g., before 6 months). UNHS has been implemented by most states in the U.S. to identify those infants whose hearing loss is more than 40 decibels below the mean (i.e., those infants with the greatest risk of impaired speech…