Vas deferens

Skip Navigation

The vas deferens is a narrow, muscular tube that connects the testicles (where sperm is produced) to the urethra. During ejaculation, the sperm flows out of the testicles, through the vas deferens, and into the tube (urethra) that leads outside the body through the penis.

Several glands, such as the prostate gland, add fluid to the sperm along the way.




The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.