Ductus deferens


The tube that transports the sperm cells from the epididymis to the ejaculatory duct is approximately 18 inches in length and 2.5 millimeters in diameter, and is known as the ductus deferens. It is a fibromuscular tube which is also commonly referred to as the vas deferens, or vasa deferentia when speaking in plural terms.

The ductus deferens takes an exit path along the scrotum to rise along the posterior edge of the testes. It makes its entry into the pelvic cavity via the inguinal canal and then passes on the medial side of the ureter after traversing alongside the bladder. The ductud deferens terminates altogether when it reaches the ejaculatory duct. This segment is known as the ampulla.

Structurally speaking, the ductus deferens is created by various layers. The outer layer is in effect three distinct layers of smooth muscle tissue. The tubular lumen terminates the inner layer, which is lined with pseudostratified ciliated columnar epithelial cells.


Ductus deferens
Image: Ductus Deferens

The pelvic plexus branches off to create the sympathetic nerves which innervate the ductus deferens. When these nerves receive stimulation, their response creates peristaltic contractions which supply the ejaculatory duct with the spermatozoa to mix with the enzymes which ultimately create semen.


The spermatic cord is the main housing structure for the ductus deferens. Its path can be followed from the testes to the inguinal canal. The overall structure of the spermatic canal is created by connective tissue, the ductus deferens, the lymph vessels, the testicular artery, the venous plexus, the cremaster muscle, and various nerves. Palpitation of the spermatic cord is most obvious where it passes just anterior to the pubic bone. The passageway which permits travel through the abdominal wall is known as the inguinal canal. This particular area is prone to hernia and other site specific injury due to its fragile weakness.
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