Anterior urethra includes the meatus, fossa navicularis, penile or pendulous urethra and bulbar urethra and the posterior urethra includes the membranous urethra and prostatic urethra.
Lies within the corpus spongiosum from the bulbous urethra to the distal penile urethra.
The bulbar urethra is positioned dorsally and begins at the root of the penis and ends at the urogenital diaphragm.
The membranous urethra extends from the urogenital diaphragm to the verumontanum
The prostatic urethra extends from the verumontanum to the bladder neck.
In women is 3-4 cm long and maintains sufficient pressure to prevent urine passage during times of physiological increases such as cough or physical activities.
Skeletal muscle in female urethra has small type 1 fibers predominantly in the middle third region of the urethra.
In women smooth muscles are present in longitudinal and circular layers.
In women-skeletal and smooth muscles contribute to baseline tone and with increased in intraabdominal pressures the skeletal muscles respond.