Which three glands secrete the protein fluids which are constituents of semen?

The three accessory glands in the male reproductive system that secretes the protein fluids which are the constituents of semen are:

1. seminal vesicles,
2. prostate gland,
3. bulbourethral glands.

These three localised glands play a role in aiding the sperm cells to enter the cervix and into the uterus to the fallopian tube where they can fertilise the egg cells. These constituents form the fluid that protects and sustains the sperms cell as to avoid them to die easy since the female reproductive system also releases fluids that protects its external and internal lining.