The tunica vaginalis is that the serous covering of the testis.It is a pouch of serous membrane, derived from the processus vaginalis of the peritoneum, that within the fetus preceded the descent of the testis from the abdomen into the scrotum.
After its descent, that portion of the pouch that extends from the abdominal inguinal ring to close the higher a part of the gland becomes obliterated; the lower portion remains as a shut sac, that invests the surface of the testis, and is mirrored on to the inner surface of the scrotum; hence it's going to be described as consisting of a visceral and a parietal lamina.
Visceral lamina
The visceral lamina (lamina visceralis) covers the bigger a part of the testis and epididymis, connecting the latter to the testis by means that of a definite fold.
From the posterior border of the gland it's mirrored on to the inner surface of the scrotum.
Parietal lamina
The parietal lamina (lamina parietalis) is much a lot of intensive than the visceral, extending upward for a few distance in front and on the medial facet of the wire, and reaching below the testis.
The inner surface of the tunica vaginalis is sleek, and coated by a layer of straightforward cuboidal mesothelial cells.
The interval between the visceral and parietal laminæ constitutes the cavity of the tunica vaginalis.