| UB | ultimobranchial body; Unna boot; upper back; urinary bladder |
|---|---|
| UCG | ultrasonic cardiography; urinary chorionic gonadotropin |
| UCPT | urinary coproporphyrin test |
| UF | film unsharpness; ultrafiltrate; ultrafiltration; ultrafine; ultrasonic frequency; universal feeder;... |
| UFB | urinary fat bodies |