Skin
mucus in your nose
hairs on the inside of your trochea and nose
saliva
poo head
You can't stop the lava flow the barriers are only used to divert it
They do not stop it but the mucus and motion of the cillia remove said microbes and dust should they get into the lungs.
The saliva and stomach acid. Both are chemical barriers:)
whashing offten
one way is the nose ,the hair and the mucous in a person's noes prevents microbes from getting in by trapping them.
with your tears
There are many barriers that may stop the flow of communication in international areas. Different languages and a time difference can delay or stop international communications.
your stomach acids fight it off and they kill the microbes. in a way this is good and bad because if it kills the bad microbes then it kills the good microbes in our body aswell!
White blood cells
Some barriers were the surround city there were three ways and side that India had because of being surrounded by water on 3 sides there barriers would stop invasion THis was Luis who gave this answer
Eat beans and fart regularily. Honestly , there's a constant exchange of microbes, bacteria, fluides and gasses between the insides and outsides of your body. A couple of microbes will not change a thing if your immune system is not compromised ...