There are three main divisions of the pharynx: the oral pharynx, the nasal pharynx, ... of the opening between the mouth cavity and the oral pharynx is a palatine tonsil, ... The epiglottis, a lidlike covering that protects the entrance to the larynx, ...
Tonsils help capture germs that are commonly swallowed, which benefits our immune system. We have many defenses similar to tonsils, though. For example we have a film over the back of our tongue that captures germs and breaks them down with an acid similar to what's found in our saliva and tears.
