Spasm, spasm everywhere!

i dunno if this is the correct word to describe this natural occurrence but i think spasm is the best word i can think of now.

Guys, when u pee, sometimes before u even done with it, u got this tingling sensation followed quickly by a spasm going from your groin area all the way up to your head, that resulted in an involuntary spastic wiggling action which i called SPASM? Sometimes u know it;s coming, yet, try as hard as u can, still cannot win the SPASM. hahah... sometimes stand side by side peeing at the guys urinals, a little embarrass one lor. The other person sure can see u SPASM.

can someone enlighten me, why do we spasm when peeing? what;s the benefit/advantage to it? And, do girls also spasm when they pee?

Ok now to another kind of spasm. Have you experienced this before :- sometimes when u are drifting into sleep, u got jolted out of your sleep by spasm? Ok this spasm is more violent than the one mentioned above. Today i kanna a big one while napping in the MRT. Ultimate embarrassment i tell u. If i am the passengers near me in the train, i would have thought that they saw a corpse jumping into life again ala Chinese vampires. Haha..

Embarrassed, i continue to close my eyes pretending to sleep, hahaha. Luckily, no more major spasm/tremor was felt, only a few aftershocks and little spasm for the rest of my rather restless nap home.

The last kind of spasm i can think of is that kind of sexual spasm. Not goin to say much because sexual topics, i is not interested to talk about.. whahahahahahah..... SEE YA!