Final answer:
The vas deferens is the narrow tube that sperm goes through after it is made. It carries sperm from the epididymis to the urethra.
Step-by-step explanation:
The narrow tube that sperm goes through after it is made is called the vas deferens, also known as the ductus deferens. It is a thick, muscular tube that carries sperm from the epididymis to the urethra. During ejaculation, the smooth muscles of the vas deferens contract to push the sperm forward.