Cavernous veins

The blood from the cavernous spaces is returned by a series of vessels (Cavernous veins), some of which emerge in considerable numbers from the base of the glans penis and converge on the dorsum of the organ to form the deep dorsal vein; others pass out on the upper surface of the corpora cavernosa and join the same vein; some emerge from the under surface of the corpora cavernosa penis and receiving branches from the corpus cavernosum urethræ, wind around the sides of the penis to end in the deep dorsal vein; but the greater number pass out at the root of the penis and join the prostatic plexus.