Why do my testicles look like that?
Most guys have a set of two testicles. Even though many people call them "balls," testicles aren't exactly round — they're more oblong, like a football. Inside each testicle is an extra-long network of tiny tubes, called the seminiferous tubules. If you uncoiled these tubes, they'd stretch out for a distance of about 1,200 feet! These tubes are where sperm is made.
Sperm are finicky — they can't be made in just any condition. The temperature has to be just right, between three to five degrees cooler than body temperature. The testicles are kept exactly in this zone by the insulating sac called the scrotum. The scrotum is covered with wrinkly skin and a lining of hair, and everyone's looks a little different. Not all scrotums look exactly alike — they can be big or small, have a little or a lot of hair, and they vary in color.
If the outside temperature gets too cold, the muscles in the scrotum contract to bring the testicles closer to the body. The opposite happens if it gets too warm — the muscles loosen up, letting the testicles hang as far away from the body as possible. Both testicles can hang at the same height, but most guys have one lower than the other or one that's bigger than the other. Either way is perfectly O.K.