Yes, it does.
Guys get morning wood because our bladders fill up during the night and begin to press against our prostate, causing arousal. Our dicks don’t just feel the sun coming up and think “My time has come”
Actually, morning wood having to do with the bladder being full isn’t true at all. Everyone with a penis (that doesn’t have some type of erection issue) experiences “morning wood” (Nocturnal Penile Tumescence in medical terms) around three to five times per night. It occurs during REM sleep, regardless of the status of one’s bladder, and is actually something doctors check on when testing for erectile dysfunction.
Some do theorize that the sensation of a full bladder in the morning can increase the, uh, extent of the tumescence, as it were, but a full bladder isn’t the cause!
Nocturnal clitoral tumescence is also a thing that happens. :D
(Source: iraffiruse, via therealycats)