The structures involved in the production of semen include the prostate, the seminal vesicles, and the bulbourethral gland, along with the testes and epididymis.

Semen is produced as a combination of secretions from the different regions of the male reproductive tract. Each fraction differs in chemical composition and function.

Spermatozoa are produced in the testes. They mature in the epididymis. The testes also produce testosterone and inhibin.

Fluid from the seminal vesicles accounts for approximately 70% of semen volume. The seminal vesicles are the source of fructose in semen. Fructose is used by the spermatozoa as an energy source.

The prostate gland supplies about 20% of the volume of semen. Its fluids include acid phosphatase and proteolytic enzymes that lead to coagulation and subsequent liquefaction of semen. The prostate also contains most of the IgA found in semen.

The bulbourethral gland produces mucoproteins that make up about 5% of the volume of semen.

The pituitary gland is not directly involved in the production of semen; instead hormones are released which stimulate the production of sperm. The urethra is not involved in the production of semen.

Which of the following are directly involved in the production of semen?