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.
You can view more details on each measurement unit: miles or km. The SI base unit for length is the metre. 1 metre is equal to 0.000621371192237 miles, or 0.001 km.