Dartos

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Dartos
The scrotum. (Label for Dartos is at bottom left.)
The scrotum. (Label for Dartos is at bottom left.)
Gray's subject #258 1238
Origin:
Insertion:
Blood:
Nerve: Genital branch of genitofemoral nerve
Action:
Dorlands/Elsevier d_02/12280192

The dartos is a layer of smooth muscular fiber outside the external spermatic fascia but below the skin.

Contents

[edit] Gender differences

  • In males it is termed tunica dartos and lies beneath the skin of the scrotum. In older males the dartos muscle loses its tone, and tends to cause the scrotum to be smoother and to hang down further.
  • In females, the same muscle fibers are less well developed and termed dartos mulierbris, lying beneath the skin of the labia majora.

[edit] Function

The tunica dartos acts to regulate the temperature of the testicles, which promotes spermatogenesis. It does this by expanding or contracting to wrinkle the scrotal skin.

  • Contraction reduces the surface area available for heat loss, thus reducing heat loss and warming the testicles.
  • Conversely, expansion increases the surface area, promoting heat loss and thus cooling the testicles.

The dartos muscle works in conjunction with the cremaster muscle to elevate the testis but should not be confused with the cremasteric reflex.

[edit] Related terms

Some dartos-related terms:

dartoic (dar·to·ic) (dahr-to'ik) of the nature of a dartos; having a slow, involuntary contractility like that of the dartos.
dartoid (dar·toid) (dahr'toid) resembling the dartos.

[edit] Additional images

[edit] External links

v  d  e
Male reproductive system
Scrotum : layers (skin, Dartos, External spermatic fascia, Cremaster, Internal spermatic fascia) | Perineal raphe | Spermatic cord

Testes: layers (Tunica vaginalis, Tunica albuginea), Appendix, Mediastinum, Lobules, Septa, Leydig cell, Sertoli cell, Blood-testis barrier

Spermatogenesis: Spermatogonium, Spermatocytogenesis, Spermatocyte, Spermatidogenesis, Spermatid, Spermiogenesis, Spermatozoon

seminal tract: Seminiferous tubules (Tubuli seminiferi recti, Rete testis, Efferent ducts) | Epididymis  (Appendix) | Vas deferens | Ejaculatory duct  Seminal colliculus

urinary tract: Internal urethral orifice | Urethra (Prostatic, Intermediate, Spongy) | Urethral crest | Urethral gland | External urethral orifice

Penis: Corpus cavernosum | Corpus spongiosum | Navicular fossa of male urethra | Glans penis | Fundiform ligament | Suspensory ligament | Foreskin | Frenulum 

accessory glands: Seminal vesicles  (Excretory duct of seminal gland) | Prostate  (Prostatic utricle, Prostatic sinus) | Bulbourethral glands 

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