Light micrograph of a section through a seminal vesicle, one of a pair of glands on each side of the male urinary bladder. The inner lining of the gland is comprised of pseudostratified columnar epithelium (bright red). Within the lining are secretory cells that produce seminal fluid, which nourishes and promotes the movement of spermatozoa through the urethra. Smooth muscle (pink) surrounds the glands and contracts to help in the expulsion of their contents. Magnification: x40 when printed at 15cm wide.