What mechanisms are in place to make sure food doesn't "go down the wrong tube" and into the windpipe?

Windpipe also called the trachea is a cartilaginous tube that connects the pharynx and the larynx to the lungs allowing the passage of air.  In this case the mechanism in place is a flap known as the epiglottis which separates the esophagus and the trachea and therefore preventing food from 'going down the wrong tube'.

Size and shape of continents

Atissue is a group of connected cells that have a similar function within an organism.