Accessory Glands of the Male Reproductive System

The three accessory glands are the seminal glands, prostate gland, and bulbourethral glands. The seminal glands are 5-centimeter-long paired organs on the bladder's posterior wall that secrete alkaline fluid rich in fructose and prostaglandins. The prostate surrounds the proximal urethra and produces slightly acidic fluid containing enzymes. The bulbourethral glands are small mucous glands that secrete thick, alkaline mucus.

Seminal gland fluid is alkaline and viscous, containing fructose, prostaglandins, and clotting proteins. This fluid nourishes sperm and promotes their motility. The extensively folded mucosa of the seminal glands forms a honeycomb labyrinth that both secretes and stores this fluid. Contraction of the external capsule empties the secretion into the ejaculatory duct during ejaculation.

The prostate is a small, rounded organ about 4 centimeters in diameter containing 30 to 50 compound tubulo-alveolar glands. It produces slightly acidic prostatic fluid rich in enzymes that prevent sperm coagulation in the vagina. The prostate surrounds the proximal urethra and is composed of smooth muscle fibers enveloping these secretory glands.

The bulbourethral glands, also called Cowper's glands, are small 10-millimeter mucous glands that secrete thick, alkaline mucus. This mucus neutralizes urinary acids in the urethra and lubricates the tip of the penis. Their secretion occurs during male sexual response erection and ejaculation, preparing the urethra for sperm passage.

During ejaculation, seminal fluid from the seminal glands and prostate mixes with spermatozoa and travels through the accessory ducts of the male reproductive system. The ejaculatory duct, a 2-centimeter-long tube, connects the vas deferens to the urethra, where the combined seminal fluid and sperm are expelled. Bulbourethral gland secretions prepare the urethra for this passage.

The prostate is composed of smooth muscle fibers that envelop 30 to 50 compound tubulo-alveolar glands. This small, rounded organ measures approximately 4 centimeters in diameter and surrounds the proximal end of the urethra. The tubulo-alveolar structure allows the glands to produce and secrete prostatic fluid containing enzymes essential for sperm function.

The seminal glands feature an extensively folded mucosa that forms a honeycomb labyrinth, maximizing surface area for secretion and storage. This 5-centimeter-long paired organ lies on the posterior bladder wall and stores alkaline fluid rich in nutrients and clotting proteins. The labyrinth structure allows efficient production and accumulation of seminal fluid until contraction of the external capsule empties it into the ejaculatory duct.