At the center of this image is the vagina, a canal composed of smooth muscle. The small opening directly above it is the urethra, which is the opening from the bladder. Below the vagina is the anus. Above the urethra is the clitoris, a body of erectile tissue that is homologous to the penis. The vagina is surrounded by the labia minora, which are surrounded by the labia majora. The pubic bone is at top. The purple tissue is a continuation of the clitoris, the crus of clitoris. The bulb of the vestibule (blue) also consists of erectile tissue. Below the bulb is a Bartholin gland, which secretes mucus to lubricate the vagina.

BO VEISLAND/SCIENCE PHOTO LIBRARY