Urethra

The urethra is a urinary tract conduit.

Function of the urethra

The urethra transfers urine stored in the bladder outside the body through the urinary meatus during micturition (passing urine).

The urethral sphincter regulates loss of urine and therefore provides continence.

The female urethra only functions to excrete urine but in men it is also part of the reproductive system as it is the exit tract for semen.

Structure of the urethra

The female urethra is approximately 3 centimetres long and has a diameter of 3 millimetres. The urethra is far longer in men (approximately 20 centimetres) as it runs the entire length of the penis. The urethra in men can be divided into three parts, from the most internal to the most external:

• the prostatic urethra;
• the membranous urethra;
• and the spongiform urethra.