When a man is sexually stimulated, friction on the glans penis and other stimuli send signals through the nervous system that result in ejaculation. At the moment of ejaculation the walls of the epididymis contract squeeze to create peristaltic waves that push sperm into the vas deferens. Nerves also stimulate the seminal vesicles and the prostate to contract which forces semen the mixture of sperm and secretions into the urethra. Muscles surrounding the urethra contract and propel semen out of the penis. To prevent semen from flowing backwards into the bladder, the muscles in the neck of the bladder tighten to close it off. Merck Manual for Healthcare Professionals. Overview of male sexual function updated Feb
The average distance and volume of ejaculate can vary from person to person. There are several factors that can influence how far a person can shoot ejaculate, and the volume they can produce. In general, younger males tend to have more forceful ejaculations, while the average volume of ejaculate is roughly 2—5 cubic centimeters, which is up to the volume of a teaspoon.
Ejaculation is the discharge of semen normally containing sperm from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation , and an essential component of natural conception. In rare cases, ejaculation occurs because of prostatic disease.