Secretions from glands of the male reproductive system support sperm in various ways.
The glands that release secretions into the male reproductive tract are:
All of these secretions support sperm in various ways. Once secretions from glands join sperm in the male reproductive tract, the fluid is known as semen.
Both the seminal vesicles and prostate gland release secretions that join the sperm to become part semen, the fluid that is ejaculated.
The bulbourethral glands release a secretion prior to ejaculation, so it is not a major component of semen.
Figure 1: A labeled illustration of a posterior view of the three glands of the male reproductive. On the left they are shown in relation to the whole male reproductive system and bladder. On the right the glands are shown in more detail.