Light micrograph of a section through a vas deferens. The vas deferens connects the epididymis with the prostatic urethra. It transports mature sperm to the urethra, the tube that carries urine or sperm out of the body, in preparation for ejaculation. The lumen (white) is lined with a single-layer of epithelial tissue. This is surrounded by three layers of muscle tissue that contract to transport the sperm to the urethra. Magnification: x100 when printed at 15cm wide.