Describe the process of ejaculation. How many sperm does the average male ejaculate contain?
During intercourse, the penis is stimulated by friction. When sufficiently stimulated, waves of contraction sweep through the smooth muscles of the epididymes, vasa deferentia, seminal glands, and urethra. The contractions are caused by nervous reflexes involving pathways of the sympathetic system. The contractions expel the mixture of seminal fluids and sperm called semen from the urethra into the vagina. One human male ejaculation contains an average of around 100 million sperm in a volume of about 3 to 4 ml of semen.
