Scrotum


Scrotum
Scrotum
Scrotum warm and cold.jpg
Human scrotum (both tense and relaxed states)
Gray's subject #258 1237
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
Precursor labioscrotal folds
MeSH Scrotum

In some male mammals the scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum.[1] It is an extension of the perineum, and is located between the penis and anus. In humans and some other mammals, the base of the scrotum becomes covered with curly pubic hairs at puberty. The scrotum is homologous to the labia majora in females.

Contents

Function

The function of the scrotum appears to be to keep the temperature of the testes slightly lower than that of the rest of the body.[2] For human beings, the temperature should be one or two degrees Celsius below body temperature (around 37 degrees Celsius or 99 degrees Fahrenheit); higher temperatures may be damaging to sperm count. The temperature is controlled by the scrotum moving the testicles closer to the abdomen when the ambient temperature is cold, and further away when it is hot. Moving the testes away from the abdomen and increasing the exposed surface area allow a faster dispersion of excess heat. This is done by means of contraction and relaxation 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 of the scrotum. The volume of sperm produced by the testes is small (0.1-0.2 ml).[clarification needed] 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 marine 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.

Diagram of 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.

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.[3]

Innervation

Nerve Surface[4]
genital branch of genitofemoral nerve anterolateral
Anterior scrotal nerves (from ilioinguinal nerve) anterior
Posterior scrotal nerves (from perineal nerve) posterior
perineal branches of posterior femoral cutaneous nerve inferior

Health issues

A study has indicated that use of a laptop computer positioned on the lap can affect sperm production negatively.[5] A common problem of the scrotum is the development of masses. Common scrotal masses include

Other conditions include:

  • Blisters: Caused by chafing or scratching of the scrotum while the scrotum is damp. Often seen in males undergoing puberty, as emerging pubic hairs cause the urge to itch. Powdering the scrotum to absorb moisture can help to prevent this issue.
  • 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:
  • Cherry angioma
  • testicular torsion
  • cello scrotum, which was revealed in 2009 to be a hoax

References

Additional images


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Look at other dictionaries:

  • scrotum — [ skrɔtɔm ] n. m. • 1538; mot lat. ♦ Anat. Enveloppe cutanée des testicules. ⇒ 1. bourse. Adj. SCROTAL, ALE, AUX , 1538 . ● scrotum nom masculin (bas latin scrotum) Enveloppe cutanée superficielle des bourses et de leur contenu, les testicules et …   Encyclopédie Universelle

  • scrotum — (n.) 1590s, from L. scrotum, cognate with O.E. scrud garment (source of SHROUD (Cf. shroud) (n.)). Isn t the sea what Algy calls it: a grey sweet mother? The snotgreen sea. The scrotum tightening sea. Epi oinopa ponton. [Joyce, Ulysses ] …   Etymology dictionary

  • Scrotum — Scro tum, n. [L.] (Anat.) The bag or pouch which contains the testicles; the cod. [1913 Webster] …   The Collaborative International Dictionary of English

  • Scrotum — (lat.), der Hodensack, s.u. Genitalien; daher Scrotocēle, Hodenbruch. Scrotalis, was sich auf den Hodensack bezieht; daher Scrotiforme nectarium, hodensackförmiges Nectarium. Scrotalarterien, s.u. Beckenarterie b) …   Pierer's Universal-Lexikon

  • Scrōtum — (lat.), Hodensack …   Meyers Großes Konversations-Lexikon

  • Scrotum — (lat.), der Hodensack (s. Hoden) …   Kleines Konversations-Lexikon

  • Scrotum — Scrotum, lat., Hodensack; Scrotokele, Hodenbruch …   Herders Conversations-Lexikon

  • scrotum — SCRÓTUM s.n. v. scrot. Trimis de LauraGellner, 13.09.2007. Sursa: DN …   Dicționar Român

  • Scrotum — vgl. Skrotum …   Das Wörterbuch medizinischer Fachausdrücke

  • scrotum — ► NOUN (pl. scrota or scrotums) ▪ the pouch of skin containing the testicles. DERIVATIVES scrotal adjective. ORIGIN Latin …   English terms dictionary

  • scrotum — [skrōt′əm] n. pl. scrota [skrōt′ə] or scrotums [L < IE * (s)kreut > SHRED] in most male mammals, the pouch of skin holding the testicles and related structures scrotal adj …   English World dictionary


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