Tunica albuginea of testis

The tunica albuginea is the fibrous layer covering of the testis.

It is a dense blue-grey membrane, composed of bundles of white fibrous tissue which interlace in every direction.

It is covered by the tunica vaginalis, except at the points of attachment of the epididymis to the testis, and along its posterior border, where the spermatic vessels enter the gland.

It is applied to the tunica vasculosa over the glandular substance of the testis, and, at its posterior border, is reflected into the interior of the gland, forming an incomplete vertical septum, called the mediastinum testis (corpus Highmori).