Why does pepper make you sneeze?

@annaleeb just asked why does pepper make you sneeze? on her twitter feed. I thought it was an interesting question...

We sneeze when something irritates certain nerve endings in our nose: sneezing is your body's way of clearing things that shouldn't be there out of your nasal passage, and is a reflex much like coughing or vomiting (which have similar purposes). When you sneeze, mucous membranes are activated to produce snot which helps to flush out the offending substance.

Pepper, more specifically one of its constituent substances piperine, is particularly irritating to those nerve endings and so is particularly effective at inducing a sneeze.

And just so this post isn't all text, here's a video of a baby panda sneezing. To my knowledge, no pepper was harmed in the making of this video.