The structure above the left testicle is the epididymis, which is part of the male reproductive duct and serves to store sperm and secrete sperm nutrients. The epididymis is a structure immediately above the testes bilaterally that is crescent-shaped and consists of the testicular output tubules and the tortuous epididymal ducts. The epididymal structures above the testes can be palpated on palpation. The epididymis consists of an expanded testicular head at the upper end, an epididymal body in the middle, and an epididymal tail at the lower end. The testicular output tubules enter the epididymal disk to form the epididymal head, which then converges to form an epididymal duct, which meanders to form the body and tail of the epididymis, which curves posteriorly and superiorly to shift into the vas deferens. The epididymal ducts have smooth muscle, so they can propel sperm toward the tail. The epididymis temporarily stores sperm, secretes epididymal fluid to nourish the sperm, and promotes further sperm maturation.