The prostate can secrete a slightly acidic or alkaline liquid called prostatic fluid. Adult males secrete about 0.5-2.0 ml every day, and most of them are excreted with urine. Nerve or chemical stimulation can greatly increase the secretion of prostatic fluid in normal adult men. Prostate fluid often contains sperm, which is intermittently discharged into urine, so it is not uncommon for adult men to contain sperm in urine. It is normal to excrete a small amount of prostatic fluid from urine every day, which is harmless to the body. Prostate is rich in neural networks and various nerve endings, which makes it closely related to all parts of the body. Therefore, prostatitis can cause various complex systemic symptoms. At the peak of sexual intercourse, within a few seconds of ejaculation, prostatic fluid is released from the glandular duct, mixed with semen and excreted. Prostate fluid accounts for 30% of semen. The physiological function of prostate plays a role through various components contained in its secretions.
Prostate fluid contains some strong protein-decomposing enzymes and fibrin-decomposing enzymes, especially a large number of hyaluronidase, which helps sperm pass through the mucus plug of cervix and the zona pellucida of egg, thus promoting the combination of sperm and egg. Chymoprotease mainly from prostate plays an important role in semen liquefaction. Another substance in prostatic fluid can make nutrients in semen easily enter sperm and convert them into energy, thus enhancing sperm mobility. Prostate fluid is alkaline, which can buffer vaginal acid secretion and help sperm survive in female reproductive tract. In recent years, some scholars have found that the prostate is also involved in endocrine function, and even think that it is an endocrine organ.
The prostate is also considered to be a sexually sensitive site. When the prostate is properly stimulated, it can cause sexual excitement. There are glands and fibrous tissues in the neck of female bladder that are homologous to the prostate of embryonic male, which are called prostate-like tissues.