The primary sex organs of the male; they produce sperm and hormones.
Their anatomical position "outside" of the body reflects a physiologic necessity: spermatogenesis (formation of sperm) requires a temperature slightly lower than that of the body.
Tunica albuginea
Fibrous outer surface of the testis
Mediastinum of the testis
Where the tunica albuginea forms a thickened ridge along the posterior aspect.
Septa extend from the mediastinum, which separate the lobules.
Seminiferous tubules
Lie within the lobules
Sites of sperm production.
Specialized cells within the lobules produce hormones that support sperm maturation.
Straight tubules
Transport sperm from the seminiferous tubules to the rete testis
Rete testis
Comprises a network of tubules within the mediastinum of the testis.
Double-layered sac that comprises a visceral layer, which is closely adhered to the tunica albuginea of the testis, and, a parietal layer, which is in contact with the innermost layer of the scrotum and spermatic cord.
The cavity of the tunica vaginalis is the space between these two layers, and contains a small amount of fluid, which allows for movement of the testicles within the scrotum.