The end of the corpus spongiosum forms the glans penis which is underneath the foreskin in uncircumcised males. The area on the bottom of the penis, where the foreskin is attached on uncircumcised men, is known as the frenulum. The urethra, the tube where urine and semen travel through, runs down the corpus spongiosum (spongy tissue), and opens at the tip of the penis. Sperm are made in the testes (ball-like organs) and stored in the epididymis (layer of tissue) around the testes. During ejaculation, sperm are pushed up the vas deferens. Fluids are added by the seminal vesicles, the prostate gland and the bulbourethral glands to make semen.