TEACHERCAST--why name it that?

well, I wanted to find a word that incorporated throwing out ideas and thoughts, shaping them and letting go of or setting them loose as well. . . in looking up possibilities on dictionary.com, the following examples were used for "cast"-

1. The angler cast his line into the river; 
2. These facts cast new light on the matter; 
3. She cast him a look of interest.
   

It seemed to fit.