The pelvis contains the final pathways of the urogenital organs. The paired (proximal) structures receive a unilateral neurovascular supply while the unpaired (distal) structures have a bilateral supply. This has clinical implications. The information gained from digital anal and rectal examination should not be underestimated. There are four pelvic regions.
The pelvic male urogenital system consists of deep and superficial (accessible but exposed) structures. The testis 'descent' during development forms a long spermatic cord - they are 'proximal' paired organs that migrate. The migration also has significant clinical implications (such as failure of normal development). A long curved urethra is protective against infection but presents difficulties with catheterization and trauma. Prostatic narrowing with age contributes to this.
The female pelvic urogenital system both parallels and differs from the male. Visceral principles remain the same but there is less external accessibility to structures. The decrease in vulnerability may raise the prospect of hidden or missed diagnoses. Vaginal examination adds a new diagnostic dimension. The short straight female urethra increases risk of infection but is easily catheterized.
Saggital Sections of Pelvis: Male.
Saggital Sections of Pelvis: Female.
Video 08-01: Overview of the Male Pelvis
Video 08-02: Overview of the Female Pelvis
The multipotent development and lengthy 'descent' of the testis make it a common source of anatomical and pathological variation. Structures migrating in development have a higher possibility of positional variation and functional impairment.
Common positional variations are:
Inversion and retractility are not pathological but may cause confusion in diagnosis. Retractile testes that can be moved into the scrotum do not require treatment.
Incomplete descent is pathological, potentially hazardous and requires surgery.
Ectopic testes develop (virtually) normally. It may require surgery due to positional increase in susceptibility to trauma.
Video 08-03: Testicular Position and Lie