From the epididymis, sperm move into the vas deferens, the begin- ning of their pathway out of the body. As sperm move through the vas deferens, a number of glands add fluids. Sperm and these added fluids make up the semen. In fact, most of the semen is not sperm. Instead, it consists mostly of fructose, a sugar that provides an additional source of energy for the sperm. Prostaglandins are also found in the semen. Prostaglandins are chemicals that cause muscle contractions to occur in the female reproductive system. These contractions help move the sperm toward the egg. In addition, semen has an alkaline pH. This high pH.
