01 / Location & anatomical relationships
On the outside of the body, in front of the scrotum in people who have this anatomy.
02 / Structure & organization
The penis contains paired corpora cavernosa and a corpus spongiosum surrounding the urethra. The spongiosum expands distally into the glans. Changes in blood inflow and outflow influence erectile tissue volume.
03 / Function
Urine passes through the urethra to leave the body.
04 / Mechanism
The urethra runs through the penis to carry urine out. It also contains nerves, blood vessels and tissue that can fill with blood. After puberty, semen can leave through the urethra at a different time from urine.
Working together: reproductive system
Bodies develop in different ways. During puberty, hormones help reproductive organs mature. A pregnancy can begin when a sperm cell fertilizes an egg cell, and development continues in the uterus.
Meet this body system →FOR DEEPER STUDY
Connect structure with function
The urethral passage and erectile tissues are anatomically distinct. The organ has urinary and reproductive roles, coordinated through different physiological mechanisms.
Check your understanding
Locate the penis in relation to its neighbors. Explain how the structural features described above support its function, then distinguish it from a nearby structure with a different role.
Keep learning
Continue with OpenStax Anatomy and Physiology for system-level study. This atlas is educational and has not undergone independent medical peer review.