Vas deferens or sperm duct is a partially coiled tube that begins from the tail of the epididymis and finally forms the ampulla which joins the duct of the seminal vesicle to form the ejaculatory duct.
Sperm ducts are about 30-35cm in length slightly coiled in the beginning but become straight as it enters the abdominal cavity through the inguinal canal.
Function: The sperm duct help in carrying mature sperms from epididymis to the urogenital tract.