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Male Genital Anatomy

Posted by on Wednesday, January 26, 2011, 1:42
This news item was posted in G, Male genital category and has 1 Comment so far.

The male genitalia is composed of the external genitalia (on the outside of the body) and the internal genitalia (buried within the body).

Male Genital Anatomy
Male Genital Anatomy

The external genitalia consists of  the penis, scrotum, and pubic hair.  The internal genitalia consists of a number of hidden glands and tubes that play a role in the production and delivery of sperm.  These include the epididymis (e), vas deferens (vas), and prostate gland (pr).  Other internal structures seen in the drawing to the left are the pubic bone (PU), the urethra (u), and the testicle (T).  For the sake of brevity, we will mostly focus on the external genitalia.

The most obvious aspect of the external male genitalia is the penis.  The penis consists of a body (shaft) and glans (head).  Under the skin (as shown in the picture of a dissected penis to the right) the body (B), or shaft, of the penis contains three columns of tissue that can fill with blood to become an erection.  The corpus cavernosum makes up the bulk of the penis tissue. At the underside of the penis is the corpus spongiosum (S) that also can fill with blood to form an erection.  Running down the center of the corpus spongiosum is the urethra.  The urethra is the tube which connects the bladder to the tip of the penis and is where both urine and semen exit.     The penis is firmly attached to the pelvic bone by two strong bands of fibrous tissue, called the root.  The root is not visible except when dissected.  In this picture of a dissected penis (looking at the underside), the skin has been removed showing some of the underlying structures.  The roots (R) join to become the body (B).

The tip, or head, of the penis is called the glans (G).  It is one of the most sensitive areas on a man’s body, containing many nerve fibers.  Unless one is circumcised, the glans is covered by a loose, hoodlike fold of skin called the foreskin (f) or prepuce.  This foreskin can be pulled back exposing the glans.  In those who are circumcised, the foreskin has been surgically removed just below the glans.  There is often a wrinkle-like scar on the shaft at the site where the foreskin was removed.

Circumcision is a controversial procedure whereby the skin normally covering the head of the penis is removed. It is commonly done for religious or cultural reasons, and in the past was believed to be medically superior to be circumcised. Recently, a number of clinical studies have shown that although circumcised men do have a slightly lower rate of penile cancer and bladder infections when compared to uncircumcised men, the difference is not significant. Most of the American medical community today believes circumcision is not necessary. Many believe it is downright cruel and disfiguring. For more information on the pros and cons of circumcision, check out the American Academy of Pediatrics policy statement on this topic.

A circumcised and uncircumcised penis. A cross-section through the shaft.

The vertical slit at the tip of the glans is the urethral meatus (m); it is the opening of the urethra (u). The urethra is a tube-like structure through which both urine and semen flow.

The base of the glans is a cone shape called the corona. Around the corona are numerous small sebaceous glands, which in latin are called glandula Tysonii odorifera.  These glands secrete a whitish material which has a peculiar odor; this cheese-like substance is called smegma.

The scrotum is a loose, wrinkled pouch that has two compartments, each of which contains a testicle.  The testicles are oval, rubbery structures that are about 4.5 cm long (range is usually 3.5 to 5.5 cm).  The left testicle usually lies somewhat lower than the right.  On the back side of each testicle is the softer, comma-shaped, epididymis (e); it feels somewhat like a bag of worms.  Sperm leaving the testicle (where it is made), flows through the epididymis (e) into the vas deferens (vas), and joins the urethra (u) in the prostate (pr).

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1 Response to “Male Genital Anatomy”

  1. Gordon
    2011.01.27 12:38

    Major lover with this site, a bunch of your blogposts have definitely helped me out. Looking forward to upgrades!

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