I'm probably in dire need of an anatomy lesson so I hope my question doesn't sound stupid. I have a question about ejaculation. I know that semen and sperm production start out in the testicals and that fluid travels up vas deferans and ejaculated out the urethra. I also know that urine comes out the urethra but obviously comes from the bladder. I've always wondered what organs were working in concert to make a male ejaculate and how does the body know when to turn on the valve for urine and off for semen and vice-versa?
The other reason I'm asking and probably don't know my anatomy correctly is that the kidneys function to get rid of urine but do they have any function during sex with ejaculation or not at all involved? I ask because I was told I have a dry kidney by doctor and the only thing I do except take lithium (which the kidney needs to break down) is sexual activity or self-stimulation at least once daily. I have masturbated almost daily since I was 10 and first able to produce semen and as long as I can remember before that with that level of frequency. I was wondering if being this active had any affect on kidneys at all and if I did things sporadically if it would help matters? Again, likely a dumb question but I'm not that great with anatomy and how the reproductive system does what it's supposed to do. Aside from drawings in health class that's all I've ever seen and never had explained then or now how the body actually functions to release semen and sperm.