An instrument is a concrete or abstract tool intended for a purpose other than mechanical work, in particular a refined one.
Musical instruments are devices designed to produce music, frequently by plucking or striking a string or bell or drum surface, or by forcing air to resonate (see wind instruments).
... the urethra is about 8 inches (200 mm) long and opens at the end of the penis.
Medical problems of the urethra:
Hypospadias[?] is a form of abnormal development ...