spongiose part of urethra
The longest part of the male urethra contained in the corpus spongiosum and extending from the end of the membranous portion to the external urethral orifice; commencing below the inferior fascia of the urogenital diaphragm it passes forward and upward to the front of the symphysis pubis; and then, in the flaccid condition of the penis, it bends downward and forward; while narrow and of uniform size in the body of the penis, it is dilated behind, within the bulb, and again anteriorly within the glans penis, where it forms the fossa navicularis urethrae; the spongy urethra is lined by pseudostratified columnar epithelium proximally, and by stratified squamous epithelium distally.