Mouth, esophagus, and stomach i am 100% sure because first you chew your food, than you swallow it, and then you digest it,
Yes I believe so
hope this helps
I would be dead any way so why worry about it go spend time with you family and ignore it family will always be there for you not some weird drugs said to cure you but ends up being the thing to kill you.
the answers will be the second line of defense and this defense is part of innate of immunity
