I came across this article giving some great information on the uvula.
It covers what people originally thought it was used for, such as how we consume food.
The actual use of the uvula is that to provide lubrication to aid human speech and singing.
I think it is worth a read: http://mentalfloss.com/article/30806/what-does-dangly-thing-back-your-throat-do.
It’s a fun article that is not overly technical but contains some good information about another part of our singing instrument.