The male accessory ducts (vasa efferentia, epididymis, vas deferens, and rete testis) serve to store spermatozoa and to transport them outside urethra during ejaculation. Male accessory glands are seminal vesicles, prostate glands, and bulbourethral glands which contribute seminal plasma to semen. Seminal vesicle secretion accounts for 60% of seminal plasma and adds alkaline pH (to counteract acidic pH of the vagina), fructose (a nutrient), mucus and coagulating and local acting enzymes. Prostate gland secretions account for 30% of plasma and add citrate (a nutrient for sperm mitochondria), calcium and a proteolytic enzyme termed as prostate-specific antigen (to liquefy ejaculate just before release). Secretion from Cowper gland adds only small volume.