Why do some tastes have accompanying physical sensation?

As the title says, I am curious why some tastes have an accompanying physical sensation. For me, there are two ways this comes up:

1. where on the tongue (e.g., something sour felt on sides of tongue or something sweet at the tip of the tongue)

2. a literal sensation (e.g., something funky, like blue cheese, that feels like a hot damp press against the back roof of the mouth or something floral feeling like a cool brush of air in the front roof of the mouth)

Thanks!