Spermatozoa are produced in the testes from puberty until death. The rate of production is 1,000 spermatozoa per second – 24x7. This slows down with age beginning in the thirties. Production of sperms takes about 72 days and it takes about 14 days for the spermatozoa to travel from the testes to the ejaculate, the semen. In the fresh semen sample, after ejaculation, spermatozoa survive only for few hours outside. Spermatozoa can survive indefinitely in the frozen semen sample. The longest recorded period is 21 years. How long they survive in the male's body is not known. The spermatozoa, after ejaculation into the woman’s vagina, move into the cervix, uterus and fallopian tubes and remain alive for about 5 days in the female reproductive system. This has been documented by identifying motile (moving) spermatozoa in the Pelvic cavity (Pouch of Douglas) by timed laparoscopy.. There is no data to indicate whether they would live longer.
Prof. N. Pandiyan, Chettinad Hospital and Research Institute, Kelambakkam, TN.
This week’s questions
Why do muscles in different parts of the body twitch?
G. Subramaniam, Chennai
Why does a plastic strainer melt when hot oil is poured on it but not boiling water or milk ?
Jennifer Navis, Bengaluru