Anatomy of the ductus deferens and spermatic cord.

Ductus deferens

The ductus deferens / vas deferens (ductus deferens) is a continuation of the duct of the epididymis (ductus epididymidis). Its length averages 40-55 cm.

It has the following parts:

Testicular or scrotal part (pars scrotalis)
Funicular part, which is part of the spermatic cord (pars funicularis)
Inguinal part, which is located in the inguinal canal (pars inguinalis)
Pelvic part, which reaches the prostate (pars pelvica)

Топография

Part of the ductus	Testicular part	Funicular part	Inguinal part	Pelvic part
Location	In scrotum	As part of the spermatic cord, in the scrotum	As part of the spermatic cord in the inguinal canal	Lesser pelvis
Holotopy	–	It is projected into the right and left inguinal areas of the anterior abdominal wall	Same as the funicular part	–
Syntopy	Superior to testis and epididymis	Posterior to testicular vein and artery, lymphatic vessels, testicular membranes, posterior artery of the vas deferens and veins	Same as the funicular part	It leaves the deep inguinal ring under the parietal layer of the peritoneum, crosses the external iliac vessels, goes back and down, where it is located between the wall of the bladder and the ureter, passes to the posterior wall of the bladder (where it forms an ampulla), which is located between the posterior surface of the bladder in front, seminal vesicles laterally and the ampulla of the rectum from behind
Relation to peritoneum	–	–	–	mesoperitoneally

Terminal part of the ductus deferens, there is a widening called ampulla (ampulla ductus deferentis)

Ampulla of the ductus deferens (ampulla ductus deferentis)

This is where the accumulation and storage of spermatozoa occurs until the moment of ejaculation.

The ampulla merges with the duct of the seminal vesicle (ductus excretorius), forming the ejaculatory duct (ductus ejaculatorius), which penetrates the central zone of the prostate and opens on the seminal colliculus in the prostatic urethra.

The wall of the ductus deferens consists of three layers.

The mucosa (tunica muscosa), which is the multi-row prismatic epithelium with microvilli, which forms longitudinal folds.

The muscular layer (tunica muscularis), which is in turn formed by three layers: the internal longitudinal layer, the middle circular layer, and the external longitudinal layer.

The adventitia (tunica adventitia), which is the external layer.

Blood supply

Arterial blood enters the ductus deferens from the artery of the ductus deferens, the middle rectal and inferior urogenital arteries (from the internal iliac artery).

Venous drainage

Venous blood drains into the vesicular venous plexus, and then into the internal iliac vein.

Lymph drainage

Lymph from the ductus deferens drains into the internal iliac lymph nodes.

Innervation

Innervation is carried out by the plexus of the ductus deferens, which is formed by branches from the abdominal aortic and inferior hypogastric plexuses, as well as pelvic splanchnic nerves.

Spermatic cord

Let’s consider the anatomy of the spermatic cord (funiculus spermaticus)

It is a complex of structures that runs from the deep inguinal ring to the superior end of the testis. Its length is 15-20 cm.

The spermatic cord includes several structures:

1. Ductus deferens (ductus deferens)

2. Testicular artery (a. testicularis)

3. Artery of the ductus deferens (a. ductus deferentis)

4. Cremasteric artery and vein (a. cremasterica et v. cremasterica)

5. Pampiniform venous plexus (plexus pampiniformis)

6. Lymphatic vessels of the testis and epididymis

7. Genital branch of the genitofemoral nerve (r. genitalis n. genitofemoralis) and the sympathetic nerves of the testis

8. Remainder of the vaginal process of the peritoneum and appendix of the paradidymis (paradidymis)

The spermatic cord has several layers:

1. The internal spermatic fascia (fascia spermatica interna), which continues from the transversalis fascia of the abdomen.

2. The cremaster (m. cremaster). This muscle is a continuation of the fibers of the internal obliqueand transverse abdominal muscles. It pulls the testis up.

3. The cremasteric fascia (fascia cremasterica). It arises from the fascia of the external oblique abdominal muscle.

4. The external spermatic fascia (fascia spermatica externa). It is a continuation of the superficial abdominal fascia. It arises from the border of the superficial inguinal ring and covers the cremaster.

The spermatic cord is formed during the descent of the testis (descensus testis) from the abdominal cavity into the scrotum. This occurs during embryonic development. In the embryo, the testes are located on the posterior abdominal wall at the level of the two superior lumbar vertebrae. At the inferior end of the testes, there is a condensation of mesenchyme, or the gubernaculum of the testis (gubernaculum testis), which consists of muscles and fibrous fibers.

At this time, a so-called closed process is formed in the peritoneum, which goes through the anterior abdominal wall into the scrotum and along the way collects the coats from all layers of the abdominal wall. The testis descends after the process even before the birth of the fetus at the 9th month. After that this process closes.

Non-descent of the testis into the scrotum is called cryptorchidism. In this case, the testis may remain in the abdominal cavity or in the inguinal canal. This condition requires surgical treatment.

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