Answer:
The relationships of the tunica vaginalis to the testis and epididymis is illustrated from the lateral view and two cross sections at the level of the head and mid-body of the epididymis. The large arrows indicate the sinus of the epididymis posteriorly. Reproduced with permission from de Kretser et.al.1982 in 'Disturbances in Male Fertility' Eds K Bandhauer and J Frick, Springer - Verlag Berlin.
The testis is covered by a thick fibrous connective tissue capsule called the tunica albuginea. From this structure, thin imperfect septa run in a posterior direction to join a fibrous thickening of the posterior part of the tunica albuginea called the mediastinum of the testis. The testis is thus incompletely divided into a series of lobules.
Within these lobules, the seminiferous tubules form loops, the terminal ends of which extend as straight tubular extensions, called tubuli recti, which pass into the mediastinum of the testis and join an anastomosing network of tubules called the rete testis. From the rete testis, in the human, a series of six to twelve fine efferent ducts join to form the duct of the epididymis. This duct, approximately 5-6m long in the human, is extensively coiled and forms the structure of the epididymis that can be divided into the head, body and tail of the epididymis (1). At its distal pole, the tail of the epididymis gives rise to the vas deferens (Figure 2).
