Tunica albuginea (testis)

The tunica albuginea (TA) forms the fibrous covering of the testis and is itself covered by the serous layer, the tunica vaginalis. The covering is total, except for at the point of attachment of the epididymis, and a small defect posteriorly where the spermatic cord vessels enter and leave the testis.

Posteriorly the tunica albuginea invaginates into the testis proper as the mediastinum testis, a fibrous structure which incompletely subdivides the testicular parenchyma into two.

Macroscopically, the tunica albuginea has a whitish-bluish hue, hence its name which is derived from the Latin for white-colored.

History and etymology

In Latin, 'albus' means white, and 'albugo', means whiteness, from which the term albuginea derives. The word 'tunica' is the Latin word meaning a tunic or coat.