The testicles, which are also called testes, are a key part of the male reproductive system. Dr. Patel, what can you tell us about the testes?
Well, Dr. Green, the testicles are two oval-shaped organs located inside the scrotum, which is the loose sac of skin that hangs behind the penis. They are attached at one end by a structure called the spermatic cord, which contains the blood vessels that supply the testicles.
The testicles make male hormones, including testosterone, and they produce sperm, the male reproductive cells. Coiled masses of tubes, called seminiferous tubules, inside the testes are responsible for producing sperm cells. The scrotum and testicles are located outside of the body in order to control the temperature of the sperm, which develop normally at a temperature slightly cooler than body temperature.
Sperm cells are stored in a long, coiled tube, called the epididymis, which rests on the backside of each testicle. The epididymis brings the sperm to maturity. During sexual arousal, contractions force the sperm from the epididymis into a long, muscular tube called the vas deferens. The vas deferens transports the sperm to the urethra in preparation for ejaculation.
Fluid from the seminal vesicles and the prostate gland is added to the sperm cells during ejaculation to make a substance called semen. Then the semen travels out of the body through the penis.