The testicular vein (or spermatic vein), the male

gonadal vein In medicine, gonadal vein refers to the blood vessel that carries blood away from the gonad (testis, ovary) toward the heart. These are different arteries in women (ovarian vein) and men ( testicular vein), but share the same embryological origin ...

, carries deoxygenated blood from its corresponding

testis A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...

to the

inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of th ...

or one of its tributaries. It is the male equivalent of the

ovarian vein The ovarian vein, the female gonadal vein, carries deoxygenated blood from its corresponding ovary to inferior vena cava or one of its tributaries. It is the female equivalent of the testicular vein, and is the venous counterpart of the ovarian ...

, and is the venous counterpart of the

testicular artery The testicular artery (the male gonadal artery, also called the internal spermatic arteries in older texts) is a branch of the abdominal aorta that supplies blood to the testis. It is a paired artery, with one for each of the testes. It is the ...

Structure

It is a paired vein, with one supplying each testis: * the right testicular vein generally joins the

; * the left testicular vein, unlike the right one, joins the

left renal vein The renal veins are large-calibre veins that drain blood filtered by the kidneys into the inferior vena cava. There is one renal vein draining each kidney. Because the inferior vena cava is on the right half of the body, the left renal vein is lo ...

instead of the inferior vena cava. The veins emerge from the back of the

, and receive tributaries from the epididymis. They unite and form a convoluted plexus, called the

pampiniform plexus The pampiniform plexus (from Latin ''pampinus'', a tendril, + ''forma'', form) is a venous plexus – a network of many small veins found in the human male spermatic cord, and the suspensory ligament of the ovary. In the male, it is formed by th ...

, which constitutes the greater mass of the

spermatic cord The spermatic cord is the cord-like structure in males formed by the vas deferens (''ductus deferens'') and surrounding tissue that runs from the deep inguinal ring down to each testicle. Its serosal covering, the tunica vaginalis, is an exten ...

; the vessels composing this plexus are very numerous, and ascend along the cord, in front of the

ductus deferens The vas deferens or ductus deferens is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube ...

. Below the

subcutaneous inguinal ring The inguinal canals are the two passages in the anterior abdominal wall of humans and animals which in males convey the spermatic cords and in females the round ligament of the uterus. The inguinal canals are larger and more prominent in males. Th ...

, they unite to form three or four veins, which pass along the

inguinal canal The inguinal canals are the two passages in the anterior abdominal wall of humans and animals which in males convey the spermatic cords and in females the round ligament of the uterus. The inguinal canals are larger and more prominent in males. ...

, and, entering the abdomen through the

abdominal inguinal ring The inguinal canals are the two passages in the anterior abdominal wall of humans and animals which in males convey the spermatic cords and in females the round ligament of the uterus. The inguinal canals are larger and more prominent in males. ...

, coalesce to form two veins, which ascend on the

Psoas major The psoas major ( or ; from grc, ψόᾱ, psóā, muscles of the loins) is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the iliop ...

, behind the

peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of meso ...

, lying one on either side of the internal spermatic artery. These unite to form a single vein, which opens, on the right side, into the

(at an acute angle), on the left side into the

(at a right angle). The left spermatic vein passes behind the

iliac colon The iliac colon is the portion of the descending colon which is situated within the left iliac fossa (between the crest of the left Ilium (bone), ilium, and the pelvic brim). It is about 12 to 15 cm long. It curves inferior-ward and medial-wa ...

and is thus exposed to pressure from the contents of that part of the bowel.

Variation

The testicular veins usually have

valves A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

. However, up to 40% of left testicular veins lack valves, and up to 23% of right testicular veins lack valves.

Clinical significance

Varicocele

Valveless testicular veins are a major contributing factor to

varicocele varicocele is an abnormal enlargement of the pampiniform venous plexus in the scrotum. This plexus of veins drains blood from the testicles back to the heart. The vessels originate in the abdomen and course down through the inguinal canal as p ...

. Since the left testicular vein goes all the way up to the left

renal vein The renal veins are large-calibre veins that drain blood filtered by the kidneys into the inferior vena cava. There is one renal vein draining each kidney. Because the inferior vena cava is on the right half of the body, the left renal vein is lo ...

before it empties, this results in a higher tendency for the left testicle to develop

because of the gravity working on the column of blood in this vein. The testicular vein may be ligated in part (a branch) or completely to treat varicocele. This is typically very safe. There is debate about whether the

should also be ligated simultaneously. Affected testicular veins can also be removed completely to further reduce recurrence rates.

Compression

The left renal vein passes between the abdominal aorta and the

superior mesenteric artery In human anatomy, the superior mesenteric artery (SMA) is an artery which arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies blood to the intestine from the lower part of the du ...

en route to the inferior vena cava, and is often compressed by an enlarged superior mesenteric artery—this is called the " Nutcracker effect".

Additional images

Image:Gray480.png, Diagram showing completion of development of the parietal veins. Image:Gray585.png, The veins of the right half of the male pelvis. Image:Gray1120.png, The relations of the viscera and large vessels of the abdomen. Image:Gray1145.png, Transverse section through the left side of the scrotum and the left testis. Image:Gray1146.png, The spermatic cord in the inguinal canal. Image:Slide6jj.JPG, Testicular vein

References

External links

* - "Posterior Abdominal Wall: Tributaries to the Inferior Vena Cava" {{Authority control Veins of the torso Scrotum