Spermatic cord

A spermatic cord (Latin: funiculus spermaticus) is either of the pair of cord-like anatomic structures found in the reproductive system of man, called the spermatic cords. In females it is (the homologous structure) the round ligament of the uterus. There are two spermatic cords, and the structure is surrounded by a lot of muscles and veins, as well as lymph nodes (for the lymphatic system). Lymph nodes help the immune system (however the testes sack is immunoprivileged, meaning that the immune system does not regulate it). The spermatic cord plays a part in testicular suspension with the cremaster, which it does in response to cold temperatures. It transports sperm with the help of the vas deferens, supplies blood to the related structures through the testicular artery, which it contains, and regulates the nervous system with the help of the genital branch of the genitofemoral nerve, which it contains. However the spermatic cord does not contain the femoral nerve. The spermatic cord has vessels called the internal spermatic artery (also known as the testicular artery) and the external spermatic artery (cremasteric artery) in and around it for blood circulation. It also helps with the cremaster reflex with these nerves and the cremaster muscle, which is contained within the cord. The spermatic cord grows after birth and hopefully reaches double its size for puberty, when the testes descend ("balls dropping"). In the scrotum, the left testi usually hangs lower than the right.

Temperature control is done by the spermatic cord and other anatomy by using involuntary reflexes (which usually try to pull the tests further away or closer to the body) to maintain a temperature 3-4 degrees celsius lower than the temperature of the body. The temperature of the testis (as well as the body as a whole) is controlled by changing the temperature of the blood, using the pampiniform plexus for example. Blood in the pampiniform plexus veins is cooled to make the genital structures colder, which the body does with the blood in blood vessels (by vessel dilation) to control temperature. The pampiniform plexus is different (slightly), and allows the blood vessels to cool down by letting them be separated only by their vessel walls. The vessels, which have blood flowing in different directions, can do this because of the pampiniform plexus. This allows exchange of heat and small molecules between the vessels. The plexus is drained by 3 or 4 veins in the inguinal canal.   

Anatomically, it sits above the iliac and femoral artery and below the external iliac artery near the genitals (penis). Near this area is the femoral sheath (a conical, funnel shaped extraperitoneal fascia, formed from the transversalis fascia), which involves the femoral vessels (which it sits anterior to) and iliac fascia (behind the femoral sheath). The sheath is an elongation of extraperitoneal fascia (makes the fascia longer) and goes away from the body. The spermatic cord supports the scrotum and testes. The spermatic cord sits just above the front margin (round ligament in females), and the inferior epigastric vessels are near the top of the rim of the femoral sheath to one side (anterolateral). The tubules (e.g. the spermatic cord) in this area form the testicular network (known as the rete testis) and are tangled together. 

 Anatomy  

The spermatic cord is formed by the ductus deferens, and runs from the abdomen (deep inguinal ring) through the inguinal canal down to each testicle. The pubic tubercle is the attachment to the medial end of the inguinal ligament. It forms part of the floor of the superficial inguinal ring and is crossed by the spermatic cord. The testes are in the scrotum. Between the spermatic cord reaching the testes, and it going through the inguinal canal, it sits anterior to the adductor longus. The adductor longus is a large (one of the three adductors, and the most anterior of them) fan-shaped muscle. 

The spermatic cord has vessels passing through the inguinal canal to reach the pelvis. Here it goes in front of the vessels of the vas deferens. This is near to the part of the vas deferens which comes after it rises out of the epididymis and has a small section of straight tube. There is a loosely arranged array (joined by connective tissue) of a muscle fasciculi called the cremaster going down the spermatic cord in males. This (cremasteric fascia) goes down, and around the testes where it is deep to the external spermatic fascia. This also helps with keeping the testes in position in males. In females, the structures keep the placenta the right way up. The seminal vesicle joins with the vas deferens (the duct of the seminal vesicle and ampulle of the vas deferens) to form the ejaculatory ducts and carries sperm from the epididymis to the urethra with the help of the spermatic cord. It also supplies the genital structures (testes and anatomy surrounding it) with a blood and nerve supply. In females, the array of muscle is on the round ligament of the uterus.


The spermatic cord contains the ilioinguinal nerve and the genital branch of the genitofemoral nerve, which are kept inside the external spermatic fascia. The cord includes the cremaster artery, veins, and vasal artery, and vasal veins, and lymph nodes of both, inside the external spermatic fascia. The arteries, veins, nerves and lymphs that supply the testes are in the internal spermatic fascia. 

The internal spermatic fascia comes from the transversalis fascia, and makes a thin, loose layer to go around the spermatic cord. The external spermatic fascia is fully connected to (it is continuous with) the abdomen wall. Between entrance to the inguinal canal and where it reaches the testis, the spermatic cord cord sits anterior to (in front of) the tendon of adductor longus. Here it is flanked anteriorly by the superficial external pudendal artery. In the same area it is posteriorly flanked by the deep external pudendal artery. The ilioinguinal nerve sits inferior as the spermatic cord goes through the inguinal canal.

The processus vaginalis, which helps during fetal development to guide the testes into the scrotum in man, usually closes after birth. This is a type of shunting. It closes the gap and connection between the abdomen and scrotum (in males) or labia majora (in females) when it shuts and does not allow the abdomen and scrotum to communicate anymore. A patent processus vaginalis (PPV) is when this does not happen, and allows transfer between the peritoneal cavity and the spermatic cord or scrotum, called a communicating hydrocele. Fluid builds up, which is called a hydrocele, and is how a PPV presents. It can also present as a hernia. A hydrocele usually fixes itself once the processus vaginalis closes (called obliviation) by 18 to 24 months of age. Also, if the processus vaginalis is obliterated further away from the body, but the communication is still open proximally (closer to the body), it may present as a hydrocele or cyst of the spermatic cord. In females, an inguinal canal PPV might cause an inguinal hernia or hydrocele, but it might present with no symptoms. It is obliterated (closed) in most adults but is sometimes patent even in to old age. 

In females, a patent processus vaginalis (PPV) in the canal can be called (referred to as) the canal of Nuck. In the canal, the spermatic cord and round ligament are covered by the external spermatic fascia. The coverings of the ligament, which in some do not reach the mons pubis, are different to the spermatic cord. The covering of the ligament blends with the ligament and are thinner. The round ligament (and ovarian ligament) develop from the gubernaculum. They are both continuous. 

The spermatic cord gets longer after birth until puberty, and should have doubled in length since birth at puberty. If the cord does not double in size, the testes will not still be in the scrotum when they descend (called the "testes dropping" in puberty of males). The spermatic cord does not keep growing forever, and growth is stable after puberty. Old age can cause changes which might sometimes become problems with time. 

Androgen exposure during pregnancy makes the spermatic cord and scrotum large compared to the other structures in the unborn baby (neonate). This is normal. The seminal vesicles and adjacent (next to) ampullae of the vas deferens become larger than the other structures because of androgen exposure. The cremaster is the thickest in young men but its size varies from person to person. 

Small accessory suprarenal nodules, sometimes called adrenal rests, might be found nearby in the areolar tissue near the suprarenal glands. These can be near the spermatic cord and related structures because of embryological migration, which is the tissue moving during development as an embryo to its final anatomical position. It happens in around 2% of the children that go through inguinal procedures, and affects the distal (further away from the body) part of the spermatic cord. They are usually oval or circle, and bright yellow to orange color, about 5 mm in diameter, and made up mostly of cortical tissue. Suprarenal nodules contain the three layers of adrenal cortex tissue (the suprarenal tissue) but no medulla. They are also sometimes found in the spermatic cord, epididymis or testis in young men and ovary or broad ligament of the uterus in young women. It is rarely the site of neoplastic change such as growths. However, the ectopic (not where it should be) suprarenal tissue might still sometimes cause diagnostic confusion.

 Muscles 

The spermatic cord can pass from the abdomen (a wall made up of layers of muscle) into the scrotum because it goes through the inguinal canal. The inguinal canal takes the spermatic cord through the wall and down into each testicle. The canal structure is made stronger with extensions (fibrous lengths like strings) coming off the boundaries of the rings in the canal, formed by the external oblique aponeurosis. The rings (the deep inguinal ring is the entrance to the canal, and the superficial inguinal ring is the exit) help keep the structure strong because of physics and allows the spermatic cord to pass. Without this canal there would be no way for the spermatic cord to get through. It is a path for other things too. In both sexes, the inguinal canal lets the ilioinguinal nerve pass, to allow the external genitalia and groin area to feel sensation such as pleasure. In females it allows the round ligament of the uterus to go toward the labia majora (plural) in the same way as in men for the scrotum. Though many people think that the round ligament (in women) ends at the labium majus (singular, meaning one labia majora), a cadaveric dissection showed that, actually the ligament ends just outside the external ring. 

Related muscles include the abdomen and rectum and other muscle structures that run through the area (near the spermatic cord). The related blood circulation drains the abdomen. Other nerves in the area pass through with the spermatic cord at some point before or after passing through the abdomen. The muscles in the area provide testicular elevation. The spermatic cord goes into the scrotum to help with this (in man) with the related structures that go with it, and with its own structure. These structures are in the body for this purpose but each structure often has a secondary purpose (function). Bringing the testes closer or more further away from the body is a way for the body to regulate temperature, as it tries to keep the testes 3 or 4 degrees celsius colder than the rest of the body. Other parts help the spermatic cord with its way of using an automatic reflex to change how much the testes hang from the body, whether it is the primary or secondary purpose of them to do so. 

Smooth muscle structures nearby include the dartos layer (of smooth muscle), which is joined together (continuously) with the Colles', Scarpa's, and dartos fascias of the penis. Layers of the spermatic cords are continuous with both the external cremasteric, and external and internal spermatic fascia of the scrotum. The fascia rises from the aponeuroses. The aponeuroses are a part of a flat muscle that is pearly, white and fibrous, and takes the place of a muscle tendon in this type of muscle). More specifically it is the aponeurose of the external oblique as well as the internal oblique, and the transversalis fascia of the abdominal wall. The spermatic cord supporting the testis is helped by the gubernaculum, which fixes them to the scrotal wall from below, at the lower pole of the sack. The gubernaculum is a band of fibrous tissue, not a muscle, like the spermatic cord or the smooth attaching the to spermatic fascia, is. 

The anterior oblique wall of the pelvis is a smooth surface facing upwards and backwards in the body. It is related to the urinary bladder. The wall also faces upwards and towards the body with smooth surfaces where it attaches to the medial thigh muscles. The anterior surface also faces inferolateral (below and to one side), with the smooth and rough surface of the wall. The rough surface goes superomedially (above and towards the middle (the midline of the body).  The symphysial surface areas (pubic symphysis areas) such as the pubic crest are elongated and oval where they are joined (united) with another bone, with cartilage. The pubic crest is the rounded upper border of the body and hangs over the anterior surface. There is also the small, rounded protrusion (something sticking out) of the lateral end of the pubic crest called the tubercle. Both the tubercle and crest can be felt and detected by touch because they are palpable. The spermatic, rising from the scrotum, crosses above the pubic crest and obscures it partly at the anterior abdominal wall.

 Nerves 


A nerve, the ilioinguinal nerve runs superficial (which means it runs closer to the surface of the body) to the spermatic cord or round ligament (in females) within the inguinal canal. The ilioinguinal nerves comes here after supplying its structure (it pierces lower down to the internal oblique it supplies). The nerve originates from the L1 (lumbar vertebrae) position on the spine. It goes from where it originates (starts) at L1 spinal towards the pelvic bone. It goes through the canal then it emerges with the cord from the superficial inguinal ring before dividing in to its terminal branches. Above this, anaesthesia can be used on the vein to make the area numb, in 4cm median (towards the center) of the abdomen and 4 cm below the anterior superior (above and in front) iliac spine, above the spermatic cord. The ilioinguinal nerve is one of many nerves that run in the front abdominal wall. Another nerve, the genitofemoral nerve also starts at the L1, L2 regions of the spine (this one being formed in the substance of the psoas major), and has its genital branch contained in the spermatic cord. After emerging from where it starts, then going down the spine, it passes posteriorly to the ureter and divides to its genital and femoral branches. It may also emerge close to (near) the psoas major. 

The genital branch is near to the spermatic cord as it crosses the lower part of the external iliac artery. It then enters the inguinal canal through the deep ring where it meets the spermatic cord or round ligament. It leaves through the superficial inguinal ring dorsal to (towards the back of) the round ligament or spermatic cord to supply the area it provides nerve endings and stimulation to (the cremaster muscle and skin of the external genitalia). The genital branch is responsible for the cremasteric reflex, as it innervates the muscle, after travelling along the spermatic cord.

 Blood vessels  
The epigastric artery penetrates (or pierces) the transversalis fascia. The fascia separates the epigastric artery and spermatic cord. The inferior epigastric artery (deep epigastric artery), which starts at the medial (towards the body) part of the external iliac artery, is posterior (behind) the inguinal ligament. It has blood vessels in the lower half (the superficial epigastric vein) which drain the abdomen of blood. Usually it is two veins. The two join together and form a single vein which drains in to the external iliac artery near the spermatic cord. The pubic branch, muscular branches, and cutaneous branches are branches of the inferior epigastric artery. The cremasteric artery is a branch of the inferior epigastric artery too. 


The inferior epigastric artery gives off (branches to) the cremasteric artery (also known as the external spermatic artery). The cremasteric artery has branches of its own too. It supplies cremaster and other coverings of the spermatic cord and other structures, and is joined with the testicular artery (also called the internal spermatic artery). It uses the testicular artery to supply blood to the cremaster and the other coverings of the cord and other local (near) anatomy. The fascia (joined together muscle and connective tissue) here is called the cremaster fascia. The fascia covers the muscle. Down the cremaster muscle (length-ways, longitudinal) it is both striated and smooth muscle fibre (bundles). The cremaster muscle covers the spermatic cord (males) or uterine (uterus) round ligament of the female with a loosely arranged array of muscle, which is then covered by the cremaster fascia. The cremaster helps blood circulation in the pelvis region. Also, sometimes the inferior epigastric artery comes up from the femoral artery. It then ascends (goes up) anterior to (in front of) the femoral vein near the spermatic cord, but then it follows its normal path across the abdomen. In rare cases it comes up from the external iliac artery (in common with an aberrant obturator artery) or from the obturator artery. The aberrant obturator is the public branch of the inferior epigastric artery when it is larger (and supplies more blood) to the area.

The cremasteric artery (external spermatic artery) comes from the inferior epigastric artery. It travels along the spermatic cord in the inguinal canal after going through the deep inguinal canal ring entrance, and travels with the testicular artery. It does this in the internal spermatic fascia, where the testicular artery is, near the vas deferens and its vessels, the cremaster muscle and its vessels, that are within the external spermatic fascia. It is, however, different and separate from the external fascia, and where the internal and external spermatic cords are (in the internal fascia), and a layer separates the internal spermatic fascia from the external fascia. The external fascia is also continuous with the abdomen unlike the internal facia, which forms a thin, loose layer around the spermatic cord.


The testicular artery (also known as the internal spermatic artery) originates from (starts at) the abdominal aorta. This is usually near the T2 (thoracic vertebrae) level of the spine. It travels inferolaterally (below and to one side) under the parietal peritoneum. The testicular artery goes from where it originates, along the psoas major to go towards the pelvis. In the pelvis, the arteries sit in front of genitofemoral nerves, urterers, and external iliac arteries. They meet the spermatic cord in the inguinal canal, after entering through the internal inguinal ring to then reach the scrotum. It is in the inguinal canal where it meets the vasal and cremasteric arteries. It reaches the scrotum ipsilaterally (on the same side of the body as) with the spermatic cord. The testicular artery gives off branches which then supply parts as it goes through the body. The testicular artery branches to an inferior testicular artery and internal spermatic arteries as it goes to the testes. The amount of branches from the testicular artery is different from person to person.

The superficial external pudendal artery and deep external pudendal artery are near to the spermatic cord while it is near the adductor longus (which here the spermatic cord sits anterior to). Before it reaches the tests, and after it is out of the inguinal canal (through the superficial inguinal ring), it is flanked anteriorly by the superficial external pudendal artery, and posteriorly by the deep external pudendal artery. The pudendal artery arises from the cribriform fascia and passes closer to the middle of the body (usually deep to the saphenous vein, a long vein in the body) and across the spermatic cord or round ligament. It supplies the parts of the body that it goes to next and anastomoses with its branches of the internal pudendal artery. The areas that the pudenda artery supply are the abdominal, penile, scrotal or labial skin.

 Related pages  
 Vas deferens
 Blood vessels
 Distraction osteogenesis (leg lengthening)

 References  


category:Anatomy of the male reproductive system