Final answer:
Retrograde ejaculation is a condition in which the male ejaculate is released into the bladder instead of the urethra. This happens when the muscles that close off the bladder during ejaculation do not function properly.
Step-by-step explanation:
Retrograde ejaculation is the condition in which the male ejaculate is released into the bladder instead of being ejaculated outside the body through the urethra. Normally, during ejaculation, muscle contractions propel sperm from the epididymis, through the ducts, and out of the body through the urethra. However, in retrograde ejaculation, the muscles that normally close off the bladder during ejaculation do not function properly, causing the semen to enter the bladder instead.