When you are thumbing a bass, the mouth is open and you can look down and see the part of what looks like "another part of the human anatomy" lol

Is this like the opening to their throat?

Also, do the bass eat prey and hold it in their mouth before that "hole" opens?

For example when they take a worm, they usually swim a few seconds before I set the hook. Sometimes they "swallow" the hook in this place.

Almost seems like the bass hold it in there for a couple seconds then swallow food. Like humans when we keep food in our mouths then swallow.

I believe what you are referring to is commonly called the gullet.

Yes. That's correct. :-)

Just looked it up. Said it was like the esophagus for the fishy.