Tunica albuginea (penis)

For other structures with the same name, see Tunica albuginea (disambiguation).

Tunica albuginea (penis)
The penis in transverse section with tunica albuginea shown
Transverse section of the penis
Details
Identifiers
Latin	tunica albuginea corporum cavernosorum, tunica albuginea corporis spongiosi
TA98	A09.4.01.017 A09.4.01.018
TA2	3593
FMA	19630
Anatomical terminology

The tunica albuginea is the fibrous envelope that extends the length of the corpora cavernosa penis and corpus spongiosum penis. It is a bi-layered structure that includes an outer longitudinal layer and an inner circular layer.

Anatomy

Microstructure

The trabeculae of the tunica albuginea are more delicate, nearly uniform in size, and the meshes between them smaller than in the corpora cavernosa penis: their long diameters, for the most part, corresponding with that of the penis.

The external envelope or outer coat of the corpus spongiosum is formed partly of unstriped muscular fibers, and a layer of the same tissue immediately surrounds the canal of the urethra.

It consists of approximately 5% elastin, with the remainder mostly consisting of collagen.

Function

The tunica albuginea is directly involved in maintaining an erection; that is due to Buck's fascia constricting the erection veins of the penis, preventing blood from leaving and thus sustaining the erect state.

Additional images

• 
  Medical ultrasonography of a normal penis

References

This article incorporates text in the public domain from page 1250 of the 20th edition of Gray's Anatomy (1918)

External links

• Anatomy photo:42:07-0103 at the SUNY Downstate Medical Center - "The Male Perineum and the Penis: The Corpus Spongiosum and Corpora Cavernosa"
• Image at downstate.edu
• Image at downstate.edu
• Histology image: 17703loa – Histology Learning System at Boston University
• Encyclopedia of Reproduction