speculum

A speculum is a medical instrument designed to widen an opening in the body to allow examination of the interior surfaces. The word comes from Latin speculum, meaning “an instrument for looking.” Specula are used to inspect mucous membranes and luminal organs and to facilitate sampling, instrumentation, or treatment.

The most familiar application is the vaginal speculum, which opens the vaginal walls to view the vagina and cervix and to collect samples such as Pap tests. Variants differ in blade shape, size, and mechanism. Common designs include the Graves two-blade speculum, the Pedersen variant with narrower blades for certain anatomies, and the duckbill style; instruments may be metal or plastic, and can be disposable or reusable. Other examples include nasal specula for inspecting the nasal passages, ear specula for the ear canal, and rectal or vaginal specula used for broader examinations.

In addition to clinical use, the term speculum appears in historical contexts discussing speculum metal, an alloy of tin and copper once used to manufacture mirrors and early instruments.

Overall, a speculum serves to retract or widen an opening to provide visibility and access for examination, sampling, or treatment across multiple medical specialties.