Prostatic urethra

{{Short description|Widest and most dilatable part of the urethra canal}}

{{Infobox anatomy

| Name = Prostatic urethra

| Latin = pars prostatica urethrae

| Image = Gray1142.png

| Caption = The male urethra laid open on its anterior (upper) surface. (Prostatic part labeled at upper right.)

| Image2 = Illu quiz prostate01.jpg

| Caption2 = 1: Vas deferens
2: Seminal vesicle
3: Base of the prostate
4: Apex of the prostate
5: Prostatic urethra

| System =

}}

The prostatic urethra, the widest and most dilatable part of the urethra canal, is about 3 cm long.

It runs almost vertically through the prostate from its base to its apex, lying nearer its anterior than its posterior surface; the form of the canal is spindle-shaped, being wider in the middle than at either extremity, and narrowest below, where it joins the membranous portion.

A transverse section of the canal as it lies in the prostate is horse-shoe-shaped, with the convexity directed forward.

The keyhole sign, in ultrasound, is associated with a dilated bladder and prostatic urethra.