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While we envision semen to be shot out in jets, does ejaculation have to be ejected?
In many cases, it is indeed ejected. But if you're seen a few for yourself, you'd know that a lot of people don't come in jets. Rather, their semen seep out, squeeze out, or even drip.
First, we need to know what muscles help with ejaculation. Ejaculation is controlled by rhythmic contraction of bulbocavernosus muscle in the penis. It acts as the pump that pushes semen out of the body!
Ejaculation starts with steady contractions spaced about 0.8 seconds in between. After 3 to 4 cycles, the contractions become weaker and more irregular. This irregularity is also affected by the penis’s own contraction. On average, the first 3 pumps of semen can shoot out in a 30 to 60 cm range, weakening quickly. People after 50 have a shorter range of 15 to 30 cm.
The trajectory of ejaculation depends on the pressure produced in the body, which factors in volume (i.e. how much semen there is), the amount of space semen passes through, and the power of propulsion. Here are some of the factors.
1. Volume of semen
Each ejaculation expels around 2 to 5 ml of semen. Smaller volumes of semen will lower the pressure and cause it to not shoot out.
2. Structure of the urethra
If the urethra is on the wider or longer side, the pressure build-up would be insufficient to push semen far away. The opening of the urethra has a bit of effect as well, in the sense that it might cause semen to not be expelled in jets, but rather like sprays. Wider dispersion could shorten its range.
3. Urethral sphincter
Normally, the urethral sphincter between the urinary bladder and the urethra contracts, preventing semen from flowing back into the bladder. But for some, the sphincter is not tightly closed, causing some semen to backflow. This is harmless to bladder health, but would affect the amount of semen expelled out of the body.
Studies indicated that in older people, the emission and expulsion phases of ejaculation is not as distinct compared to younger individuals. One could understand it as semen making and ejecting happening simultaneously, which causes semen to seep rather than shoot. Studies also found that the longer an erection is maintained in an older male, the higher the chance that semen is seeped out. Therefore we could conclude that older people are more likely to experience a flow of semen!
The idea to take home is that ejaculation doesn't have to be ejected~ Even if it comes in jets now, you might experience it in slower flow later on. Ejaculation is like shooting for the goal - you don’t always have to shoot hard. A ball slowly rolling in can also make the goal!