Male Anatomy © Robert J. Atkins, Ph.D.

Penis

How do people alter their genitals? Piercings Tattoos Circumcision Surgical penile enlargement

Piercing Prince Albert

Piercing Ladder

Tattoos

Circumcision Egyptian

Why is cleaning foreskin helpful? Pull back foreskin Remove smegma Avoids smegma build-up

How is the penis constructed?

What are the three cylinders? 2 larger cavernous bodies 1 smaller spongy body Forms head of the penis

Penis- spongy body

Penis dissection

What is the most sensitive parts of the penis? Coronal ridge Frenulum

Penis, prostate dissection

Do you remember? Why is cleaning an uncircumcised foreskin helpful? How is the penis constructed? What are the three cylinders? What are the most sensitive parts of the penis?

What about penis size? Not related to sexual satisfaction Possibly diameter rather than length Small flaccid penis usually increases more during erection than larger flaccid penis

What is the average penis size? 5 ½ - 6 “

How does the penis compare to the vagina in size?

Penis enlargement

Penis enlargement

Penis cones

How much does penis size vary?

Penis size variations(larger)

Penis size variations (smaller – Micro-penis)

What is penis augmentation surgery? Done by cutting the ligaments that attach the root to the pubic bone. Not recommended

Penis enlargement results Before After

What causes the scrotum to move closer to the body? Sexual arousal Cold temperatures Fear Stroking inner thighs Cremasteric reflex Cremasteric muscle

What about the testes? Asymmetrical Heat reduces sperm production Left usually lower Heat reduces sperm production Best at 93 degrees

Do you remember? Does a small flaccid penis, and a large flaccid penis enlarge equally during erection? What is done in penis enlargement surgery? What causes the scrotum to move closer to the body? What can you tell me about the testes?

What is cryptorchidism? Undescended testis Prevents sperm production - too warm

What are the Seminiferous tubules? Site of sperm production Interstitial (Leydig’s) cells produce androgens Sperm = 1% of semen

Seminiferous tubules

What does the epididymis do? Storage of sperm

What do the Vas Deferens do? Moves sperm from scrotum to ejaculatory duct Within prostate gland

Do you remember? What is cryptorchidism? What are the seminiferous tubules? What does the epididymis do? What do the vas deferens do?

What are the seminal vesicles? At end of each vas deferens Alkaline fluid Major portioin of seminal fluid

What is the difference between sperm and semen? Semen (What comes out) 70% = Seminal vesicles 30% = Prostate gland 1% = Sperm 1 teaspoon 200-500 million sperm per ejaculation Sperm

Prostate gland Some semen contribution

Cowpers (bulbourethral) glands Distilate of love May contain active, healthy sperm Can produce pregnancy without ejaculation

What is the course of sperm? Testes Epididymis Vas Deferens Seminal vesicles Urethra

What causes erections? Process of tumescence Nighttime erections Related to REM sleep Rapid eye movement 90 minute cycle Not related to a full bladder

Do you remember? What do the seminal vesicles do? What is the difference between sperm and semen? What may the cowpers gland contain? What is the course of the sperm? What causes nighttime erections?

What are the stages of ejaculation? 2 phases Emission Fluid in ejaculatory duct Expulsion Semen expelled Dry orgasm Before puberty

What is retrograde ejaculation? Semen expelled into bladder May result from Prostate surgery Certain drugs Congenital abnormality

What can you tell me about testicular cancer? One of the most common cancers among young men - 15-34 age group Survival rate very high if detected early Genital self-exam recommended To identify early symptoms Lumps on testes

Do you remember? What are the stages of ejaculation? What is retrograde ejaculation? Why is a genital self-exam recommended?

What problems does the prostate cause? Prostate cancer Second leading cause of cancer deaths in men Prostate enlargement

How can you detect prostate cancer? Detected by Digital rectal exam (DRE) Blood test – Prostate Specific Antigen test (PSA test) Ultrasound Digital exam

Do you remember? What problems do the prostate cause? How can you detect prostate cancer?