Hi
I would like to learn the mechanization of ejaculatıon of pre-cum and cum, and why the color of sperm some times yellowish and some times white, and some times transparent.
Hi Smart,
Precum isn't really "ejaculated." It's more of a secretion from the Cowper's gland at the base of the penis. It releases fluids to clean the urethra and neutralize the acidity - to help the sperm. Most men are not conscious of this happening and during sex it may be difficult to tell that it happened due to vaginal fluids.
During ejaculation lots of things happen but basically, the bulbospongiosus muscle begins a series of contractions that help propel the semen out. It actually originates in the spinal cord, not the brain.
It is normal for semen to change colors. Yellowish is usually "older" semen, if you haven't ejaculated recently. Semen can appear clear, usually in younger men that are in the earlier stages of puberty but it can happen anytime.
Hope it helps.