Anatomy of the Urethra

Histological features

The epithelium of the urethra starts off as transitional cells as it exits the bladder. Further along the urethra there are stratified columnar cells, then stratified squamous cells near the external urethral orifice.
There are small mucus-secreting urethral glands, that help protect the epithelium from the corrosive urine.

Length of the urethrae

The female urethra is about 4 cm in length.There is inadequate data for the typical length of the male urethra, however a study of 109 men showed an average length of 22.3 cm (SD = 2.4 cm), ranging from 15 cm to 29 cm.