Lecture Notes

The epididymis and the vas deferens are the ducts that carry sperm from the testicles to the urethra for ejaculation. The seminiferous tubules merge to form the epididymis. The epididymis is a comma-shaped structure consisting of a coiled tube about 20 feet long. In the epididymis is where sperm finally mature. Each epididymis merges into a vas deferens, which is a tube about 18 inches long that extends into the abdominal cavity. The vas deferens joins the ejaculatory duct within the prostate gland. Because the vas deferens can easily be felt within the scrotal sac and is vital for sperm transport, it is usually the point of sterilization for men. The operation is called a vasectomy. A man is still able to ejaculate semen after the procedure; it just no longer contains sperm. At the back of the bladder lie two glands, each about the size and shape of a finger. These are the seminal vesicles, and they secrete a fluid that makes up about 60% of the seminal fluid.