The Male Genital System serves two functions: urination and reproduction. As opposed to our discussion of the Female Genital System, where the urinary and genital systems are fairly separate, in the Male the organs overlap.
Diagram — The Male Genital System

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In terms of urination, see our Diagram: The Urinary System.ย In the diagram above, at the top we see one of two Ureters which carry urine from the Kidney to the Bladder, where itโs stored.ย Once it fills enough, nerves send a message to the Brain alerting us that we need to urinate (they can also tell the bladder itself directly, in which case urination would be involuntary).
Urine travels in a tube called the Urethra, which exits the Bladder, then runs through the Prostate Gland, and down the Penis. Since the Prostateโs purpose is to nourish sperm, it is a conduit for both urine and semen. As such, it can interfere with urination.
Sperm are manufactured in the Testicle (a.k.a. โTestis,โ plural โTestesโ).ย They then mature in the Epididymis, which lies behind and on top of the Testis, after which they begin a 3-month journey up the Vas Deferens to the Prostate.ย In the Prostate, sperm are nourished by semen which is produced by the Prostate, by the two Seminal Vesicles (one on each side), and Cowperโs Glands (not shown).ย
With ejaculation during sex, the Prostate propels semen down the urethra and out. If the Prostate is surgically removed (perhaps for cancer), the Penisโs nerves and blood vessels can still allow many men to experience erection and orgasm. But there wonโt be any semen, so and conceiving a child (reproduction) would be impossible without extracting and banking sperm ahead of time.
Diseases Affecting the Male Genital System
Penis:
- STDs: Herpes, Genital Warts, Primary Syphilis, Pubic Lice (actually in the surrounding pubic hair)
- Yeast (on the head of the penis (the Glans), called Balanitis
- Foreskin: Phimosis (always too tight), Paraphimosis (gets stuck, an emergency)
- Peyronieโs Disease (twisted painful erections; uncommon)
- Cancer (very rare)
- Erectile Dysfunction (โimpotenceโ) due to problems with nerves, blood vessels, or often psychological issues
Urethra:
- Urethritis from STDs: Gonorrhea, Chlamydia, Mycoplasma genitalium
Testicle:
- Infection (called โOrchitisโ) โ usually same bacteria causing UTI
- Torsion (twisting) โ severe sudden pain, vomiting.ย A surgical emergency
- Undescended (testis never drops down; in children)
- Cancer (very uncommon; treatment successful)ย — needs ultrasound for new lumps
Scrotum:ย Benign findingsย (can confirm by ultrasound if in doubt)
- Hydrocele
- Varicocele
- Spermatocele
Epididymis:
- Epididymitis (infection) from STDs
- Epididymitis (inflammation), unknown causes but benign (same link as above)
Vas Deferensย —ย Vasectomy performed on this
Seminal Vesicles โ only if involved from invasive prostate cancer
Prostate Gland: