dilatator

Dilatator is a term used in anatomy and medicine to denote a structure or instrument that increases the diameter of a passage or opening. The word comes from Latin dilatator, derived from dilatare meaning to enlarge, and is used in English mainly in anatomical names and in references to dilating devices.

In anatomy, dilators are muscles or muscular groups that widen an opening. The best-known example is the dilator pupillae, a smooth muscle in the iris that enlarges the pupil in response to sympathetic stimulation. Other examples include nasal dilator muscles, collectively referred to as the dilatator nasi, which widen the nostrils, and various other dilator components associated with the airways or digestive tract.

In clinical practice, dilators are instruments designed to widen a body passage gradually. Cervical dilators, urethral or ureteral dilators, and gastrointestinal dilators are used to treat strictures or to prepare passages for procedures. These devices range from progressively sized rods or catheters (such as Hegar dilators or bougies) to inflatable or expandable dilators. The procedure of widening a passage is called dilatation or dilation.

The term dilatator may appear as a general descriptor for a dilating structure or instrument and can be used interchangeably with dilator in many contexts. In anatomical naming, the form dilatator (often with -dilatator or -dilator suffix) signals a role in enlargement rather than a specific muscle class.