Male reproductive system
The male reproductive system is made up of the external genitalia.
The shaft of the penis consists of two erectile bodies called the corpus cavernosum, which comprises a mass of smooth muscle, and endothelial-lined vessels and spaces (lacunae), richly supplied with nerve endings. The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa and is surrounded by the corpus spongiosum. The enlarged, bulbous shaped end of the corpus spongiosum forms the glans penis. The foreskin is a loose fold of skin that adults can retract to expose the glans penis. The frenulum is the area under the penis where the foreskin is attached.
The testes hang outside the abdominal cavity of the male within the scrotum. They begin their development in the abdominal cavity but descend into the scrotal sacs during the last two months of fetal development. This is required for the production of sperm because internal body temperatures are too high to produce viable sperm. The testes also produce the male sex hormones.
The epididymis is a mass of tightly coiled tubes cupped against the testicles. It acts as a storage place for sperm before they enter the vas deferens - tubes that carry sperm from the testes to the urethra.