The urogenital opening is where waste products of the body and reproductive fluids are expelled to the environment outside of the body cavity. In some organisms, including birds and many fish, discharge from the urological, digestive, and reproductive systems empty into a common sac called the cloaca. In many organisms, these three systems are more separated. In the human female, separate orifices have evolved for all three, while in the male, a common "urogenital orifice" discharges both urinary and reproductive fluids from the urethra.
Famous quotes containing the word opening:
“The Heavens. Once an object of superstition, awe and fear. Now a vast region for growing knowledge. The distance of Venus, the atmosphere of Mars, the size of Jupiter, and the speed of Mercury. All this and more we know. But their greatest mystery the heavens have kept a secret. What sort of life, if any, inhabits these other planets? Human life, like ours? Or life extremely lower in the scale. Or dangerously higher.”
—Richard Blake, and William Cameron Menzies. Narrator, Invaders from Mars, at the opening of the movie (1953)