Again, many male urogenital structures are more understandable when viewed from a bisected, mid-sagittal section (Figure 4-6).

Begin this journey by finding the urinary bladder and its ureters. At the inferior end of the bladder, find the very beginnings of the urethra as it courses through the prostate gland.

Try to find the seminal vesicle projecting lateral and inferior to the urinary bladder. Verify its identity by finding the ductus deferens that lay just superior to the seminal vesicles.

The secretions of the seminal vesicles and those of the ductus deferens empty into the prostatic urethra through the ejaculatory ducts. The ejaculatory ducts also course through the substance of the prostate gland and may be difficult to see if you do not have a midsagittal plane.

Follow the urethra even more distal and observe it leave the inferior aspect of the prostate, pierce the pelvic diaphragm, and become encased within the corpus spongiosum of the penis. The urethra ends at the external urethral opening found in the distal end of the corpus spongiosum, the glans penis.

You should also see one of the corpora cavernosa superior or posterior to the corpus spongiosum.

Posterior to the prostate easily identify the rectum.

Finish this exercise by finding the internal and external iliac artery, and the common iliac artery. Deep and medially to these arteries find the internal and external iliac veins and the common iliac vein.