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.
Metric measurements. A meter has been officially defined to be the distance traveled by light in a vacuum in 1/299,792,458 second. All other length and distance measurements in the metric system derive from the meter (eg. km= 1000m, 1m= 1000mm).