Originally Posted by NovexusPrime
If I had to say, I would guess it's the blood rushing about the lower limbs. A female orgasm is a severe expulsion of blood from the genitals. So there's that
I thought orgasms for both male and female had to do with various nerve networks between the genital area, and the base of the spine, thus communicating up to the brain.
To be fair though I've never actually studied the change in blood flow in a women at the moment of orgasm, and perhaps both of these things occur they aren't exactly mutually exclusive to each other.