Anatomy of a person assigned male at birth

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External Anatomy

This is the external, or outside the body, anatomy of a person assigned male at birth.

External anatomy of a person assigned male at birth

Penis/Foreskin (pink)- The penis sits outside of the body. People are born with a foreskin that covers the penis. Some people have the foreskin removed for cultural or religious reasons. This process happens when the person is a baby and is called circumcision. Someone who is circumcised has had their foreskin removed and someone who is uncircumcised still has their foreskin. Both are normal and neither one is better.

Urethral Opening (magenta)- There is an opening at the tip of the penis where urine, semen, and pre-ejaculatory fluid (or pre-cum) leave the body.

Internal Anatomy

Here is the anatomy inside the body. This image is as though someone is cut down the middle from a profile view.

Internal anatomy of a person assigned male at birth

Scrotum (teal)- The scrotum holds the testes and sits outside the body.

Testes (green)- People with a penis have two testes that produce sperm and the hormone testosterone. Once a person hits puberty, millions of sperm are produced in their testicles every day. The testes are held in the scrotum.

Epididymis (lavender)- The epididymis is where sperm are held once they are produced in the testes. They mature and grow here.

Vas Deferens (light pink)- The vas deferens connect the epididymis to the seminal vesicle and prostate and then to the urethra. The vas deferens bring sperm from the epididymis where it meets with prostate gland fluid and seminal vesicle fluid to create seamen. The vas deferens then connect to the urethra for the semen to leave the body.

Prostate (yellow)- The prostate creates fluid that combines with sperm and is part of semen

Seminal Vesicle (pink)- The seminal vesicle creates fluid that combines with sperm and is part of semen.

Cowper’s Glad- The Cowper’s glad is a small gland that produces pre-ejaculatory fluid. This fluid cleans out the urethra prior to ejaculation to make sure the sperm is not affected by any acid in the urethra.

Urethra (peach)- The urethra connects to the bladder and the vas deferens and is the tube where urine, seamen, and pre-ejaculatory fluid leaves the body.

Penis (bright pink)- During arousal, the penis fills with blood and becomes erect or hard.