The Male Anatomy

Ductus Deferens

The ductus deferens are apart of the male genitals.  They are a continuation of the duct of epididymis.  The ductus deferens is the primary components of the spermatic cord and its cordlike structure is due to its thick walls.  The ductus deferens goes through the anterior wall of the abdominal cavity via the inguinal canal.  In addition it runs along the lateral wall of the pelvis and finally retires when it joins the seminal gland and forms the ejaculatory duct.  The ductus deferens are the only structure to come into contact with the peritoneum.  The ductus deferens also cross superior to the ureters where it runs in between the ureter and the peritoneum of the ureteric fold to gain access to the bladder.  The ductus deferens begin by running posterior to the bladder and superior to the seminal gland but then descend to the medial border of the seminal gland and ureter.  This is where the ductus deferentia enlarge and form the ampulla of the ductus deferens.

Male sterilization is a common procedure performed on males to inhibit pregnancy from occurring.  It is a simple out patient procedure, and involves the ligation of the ductus deferens through an incision in the superior portion of the scrotum.  The fluid formulated by the seminal gland, bulbourethral gland, and the prostate will now contain no semen.  Since sperm are no longer ejaculated, they are destroyed in the epididymis and the proximal part of the ductus deferens.

Prostate

The prostate is a walnut shaped gland in the male reproductive organ system.  The matrix of the prostate is 2/3 glandular and 1/3 fibromuscular.  The fibrous capsule of the prostate contains the vascularization part of the gland.  The blood supply of the prostate is the prostatic arteries and these branch off of the internal iliac artery especially the inferior vesicle arteries and the middle rectal arteries.  The venous drainage of the prostate all form together to make the prostatic venous plexus.  Which lies between the fibrous capsule and the prostatic sheath.  The prostate also can be divided into right and left lobes with the separation of these lobes being the isthmus of the prostate.  Each lobe has the following four lobules:  inferoposterior lobule, inferolateral lobule, superomedial lobule, and anteromedial lobule.  The third and fourth lobule actually arises from an embryonic middle lobe.  Some clinicians refer to this section as the central zone.  The prostate also contains prostatic ducts (20-30) and these ducts flow into the prostatic sinuses that reside on each side of the seminal colliculus.  The fluid produced by the prostate accounts for 20% of the milky fluid in semen.  This fluid also has a role in the activation of sperm. 

Prostate cancer is a major cancer that has been at the forefront of research.  It occurs when cancer cells begin to reproduce uncontrollably.  Prostate cancer is generally slow moving but can metastasize to other parts of the body in aggressive cases.  It has been found that genetics and the diets of males can play a part in the formation of prostate cancer.  I have first hand witnessed an aggressive case of prostate cancer in my own cadaver.  His prostate had metastasized into his abdominopelvic cavity, and in his thoracic cavity with large tumors. 

3-D photo of prostate cancer

Innervation of the Male Genital organs

The male genitals are highly innervated throughout the seminal glands, ejaculatory ducts, and prostate.  Presynaptic sympathetic fibers begin at T12-L2 and fibers travel to become part of the lumbar splanchnic nerves, hypogastric plexus and pelvic plexus.  The presynaptic parasympathetic fibers that originate at S2-S3 follow to the pelvic splanchnic nerves, which join the inferior hypogastric and pelvic plexus as well.  The parasympathetic and postsynaptic sympathetic fibers synapse within these plexuses in their journey to the pelvic viscera.  During an orgasm, sympathetic system plays an important role in stimulating the urethral sphincter to inhibit retrograde ejaculation.  In addition, it also causes peristaltic contractions of the ductus deferens, seminal glands, and prostate that provide the vehicle for moving semen out during ejaculation.  The parasympathetic function in the internal male organs is still unclear.  However, it is known that the parasympathetic fibers ultimately form the cavernous nerves that pass to the erectile bodies of the penis are the known component of an erection. 

Pudendal Nerve Entrapment

Pudendal nerve entrapment is not common but occurs when the pudendal nerve has been compressed.  The chronic pain associated with PNE causes urinary incontinence, genital numbness, and fecal incontinence.  It is common in cyclists who sit for long periods of time.  Standing, changing positions, or sitting on a toilet seat, can relieve it.  If pain continues, MRI’s can be useful at diagnosing the issue.  If it is a positional issue when lying or standing, then it can be attributed to a tunneling syndrome.