The scrotum is sac of skin and smooth muscle that encases the testicles. The female equivalent of the scrotum is the labia majora or large lips. If an infant is going to be a male, the labia majora (labioscrotal folds) fuse together in a line that’s called the raphe, which is visible when looking at the scrotum. In women, there is no raphe and the labia majora remain open. The scrotum sits there empty until the last weeks of pregnancy, when the testicles descend from the abdomen down into the scrotum. Some people mistakenly believe the scrotum holds the testicles in place like a bag holds marbles, and if you were to cut open the scrotum, the testicles would drop out. That’s not the case, as the testicles are attached to the abdomen by the spermatic cords, which are made of tough connective tissue. The spermatic cords contain the blood vessels, nerve and lymphatic tissue for the testes, as well as the vas deferens, which delivers the sperm to the urethra. The spermatic cords are also surrounded by the cremaster muscles. It’s the spermatic cords and the structures inside of them, as well as the cremastor muscles, that hold the testicles in place, and not the scrotum. The scrotum does contain connective tissue and the dartos muscle which is what makes the scrotum wrinkle or pucker when the outside temperature is cold and the testicles need to be warmed up. The cremaster and dartos muscles also cause the testicles to raise up when a man is very aroused and is about to have an orgasm.