Home » Male Anatomy

Male Anatomy

Some of the sex and reproductive organs of boys and men are visible and external. Some are inside the body and are not visible. Outside, men have a penis and a scrotum. The scrotum contains the testicles. Hidden inside the body are several glands that help to produce semen.

The penis consists of the shaft and the glans (the head). Running through the inside of both is a long thin tube called the urethra. Urine or semen from inside the body travels through the urethra to the outside. The shaft also contains muscle and three tubes of erectile tissue, which have a lot of empty space in them. During an erection, blood flows into these spaces, making the penis stiff.

Some men have a foreskin that covers the head of the penis. The foreskin usually retracts during erection. Other men have had this skin removed, during a procedure called circumcision. Penises with and without foreskin look different but work basically the same way. If parents want their son to have a circumcision, it is usually done shortly after birth.

The two testes (testicles) produce and store sperm starting at the time of puberty. The testes hang away from the body in a bag of muscle and skin called the scrotum. During sexual excitement, sperm move out of the testes and into the urethra through tubes called the epididymis. They mix with several fluids to produce semen, which comes out of the penis through the urethra when a man ejaculates.

The prostate gland lies behind and below the penis, near the rectum. The prostate makes the fluid that provides nutrients to sperm. Two other internal glands called the seminal glands, produce a liquid that has a similar function. Sperm and these liquids combine at the time of ejaculation to form semen.

Check out our diagrams of the male and female anatomy!