Question

Animal body has a capacity of recognising self and foreign materials and it immediately rejects and destroys the foreign materials or cells by the help of body immune system.
Then why not the sperm is rejected or destroyed by the female immune system when it enters her body?

Answer 1

Dear student,,Sperms are foreign to both the man who produces them and the woman who receives them. In healthy men, sperms do not come in contact with blood. The blood-testis barrier formed by the Sertoli cells in the testes keeps the sperm away from the blood stream. Breach of this barrier, as in the case of infections or injury, may lead to the formation of anti-sperm antibodies in men. Besides, semen also contains immune-suppressive agents secreted by seminal vesicles (accessory structure). Like in the case of men, the sperms do not come in contact with blood once deposited in the vagina. Hence, no immune response against the sperms is caused in the woman. In normal women, sperms are deposited in the vagina and they gain access to the cervix and uterus within minutes. The acidic environment in the vagina kills the remaining sperms.