Misplaced Pages

This is an old revision of this page, as edited by Andrea105 (talk | contribs) at 03:12, 4 November 2009 (Revert to the revision prior to revision 323826064 dated 2009-11-04 03:11:08 by Hornswaggle69 using popups). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Scrotum" – news · newspapers · books · scholar · JSTOR (June 2008) (Learn how and when to remove this message)

Scrotum
The scrotum. On the left side the cavity of the tunica vaginalis has been opened; on the right side only the layers superficial to the Cremaster muscle have been removed.
Details
Precursor	labioscrotal folds
Artery	Anterior scrotal artery & Posterior scrotal artery
Vein	Testicular vein
Nerve	Posterior scrotal nerves, Anterior scrotal nerves, genital branch of genitofemoral nerve, perineal branches of posterior femoral cutaneous nerve
Lymph	Superficial inguinal lymph nodes
Identifiers
MeSH	D012611
TA98	A09.4.03.001 A09.4.03.004
TA2	3693
FMA	18252
Anatomical terminology[edit on Wikidata]

In some male mammals the scrotum (also referred to as the cod) is a protuberance of skin and muscle containing the testicles. It is an extension of the abdomen, and is located between the penis and gooch (the area between the penis and the anus). In humans, and some other mammals, the base of the scrotum becomes covered with curly pubic hairs at puberty. In common speech, the scrotum is often improperly referred to as the testicles, which actually refer to organs encased inside the scrotum. The scrotum is homologous to the labia majora in females. It becomes tight when sexually aroused.

Function

The function of the scrotum appears to be to keep the testis at a temperature slightly lower than that of the rest of the body. For the human, a temperature should be one or two degrees below the body temperature - 36.8 degrees Celsius (98 degrees Fahrenheit); higher temperatures may be damaging to sperm count. The temperature is controlled by moving the testicles closer to the abdomen when it is cold, and away when hot, moving the testes away from the abdomen and increasing surface area allowing a faster dispersement of excess heat. This is done by the contracting and relaxing of the cremaster muscle in the abdomen and the dartos fascia (muscular tissue under the skin) in the scrotum. However, this may not be the main function. The volume of sperm produced by the testes is small, (0.1-0.2 ml). It has been suggested that if testes were situated within the abdominal cavity that they would be subjected to the regular changes in abdominal pressure that is exerted by the abdominal muscles. This squeezing and relaxing would result in the more rapid emptying of the testes and epididymis of sperm before the spermatozoa were matured sufficiently for fertilization. Some mammals--elephants and sea-mammals, for example--do keep their testes within the abdomen and there may be mechanisms to prevent this inadvertent emptying.

Contraction of the abdominal muscles, and changes in intra-abdominal pressure, often can lift and lower the testicles within the scrotum. Contraction of the muscle fibers of the dartos tunic (or fascia) is completely involuntary and results in the appearance of increased wrinkling and thickening of the scrotal skin. The testicles are not directly attached to the skin of the scrotum, so this dartos contraction results in their sliding toward the abdomen. They also, in some men, can be lifted the same way by tightening the anus and pelvic muscles, doing Kegel exercises.

Although the ideal temperature for sperm growth varies between species, it usually appears, in warm-blooded species, to be a bit cooler than internal body temperature, necessitating the scrotum. Since this leaves the testicles vulnerable in many species, there is some debate on the evolutionary advantage of such a system. One theory is that the impregnation of females who are ill is less likely when sperm is highly sensitive to elevated body temperatures.

An alternative explanation is to protect the testes from jolts and compressions associated with an active lifestyle. Animals that have 'stately' movements - such as elephants, whales, and marsupial moles - have internal testes and no scrotum.

Health issues

This article is in list format but may read better as prose. You can help by converting this article, if appropriate. Editing help is available. (June 2008)

A common problem of the scrotum is the development of masses. Common scrotal masses include

• Sebaceous cyst, also called an epidermal cyst
• hydrocele
• hematocele
• spermatocele
• varicocele

Other conditions include:

• contact dermatitis: may cause redness, burning, swelling, and itching of the entire scrotum. Can result from soaps, solvents, detergents, and natural irritants such as poison ivy.
• inguinal hernia
• yeast infection
• swelling resulting from conditions external to the scrotum, including:
  • heart failure
  • kidney or liver disease
• Cherry angioma

References

1. "Science : Bumpy lifestyle led to external testes - 17 August 1996 - New Scientist". Retrieved 2007-11-06.

Additional images

• Structure of the male genitalia.
• Vertical section of bladder, penis, and urethra.
• The superficial branches of the internal pudendal artery.

See also

• Perineal raphe
• Erogenous zone
• Sex organ
• Castration
• Blue balls
• Scrotoplasty

• Articles needing cleanup from June 2008
• Articles with sections that need to be turned into prose from June 2008
• Male reproductive system