An urologist, for a case of erectile dysfunction, decides a direct injection of prostaglandin E1 into the penis. Injection is generally performed directly into the corpus cavernosum. During the procedure, the needle would pass through which of the following layers in order

The needle would pass, sequentially through the skin, superficial fascia of the penis, deep (Bucks) fascia of the penis, and tunica albuginea. The superficial fascia of the penis is superficial to the deep (Buck's) fascia of the penis. Daos fascia is continuous with the superficial fascia of the penis as well as the superficial fascia of the scrotum and would not be the deepest layer pierced by the needle The tunica albuginea is the deepest layer surrounding the corpora cavernosa.