Breathing is then done through the tube, bypassing the mouth, nose, and throat. A tracheostomy is commonly referred to as a stoma. This is the name for the hole in the neck that the tube passes through.
A millimeter (mm) is the smallest. In order from smallest to largest they rank millimeter, centimeter (cm), decimeter (dm), and meter (m). These are all common units of length in the metric system.
The length measurement was introduced to measure distance between any two objects. The base metric (SI) measurement unit of length is a meter. The meter is defined as the distance traveled by light in vacuum during 1/299 792 458 of a second.