CASE 5.1 RUPTURED URETHRA
A 12-year-old boy is admitted to the emergency department with complaints of a painful, enlarged scrotum and mild distention of the lower abdomen. Relevant Clinical Findings History
The patient relates that 30 hours earlier, while racing with friends, his foot slipped from the pedal of his bicycle and he came down hard, straddling the bicycle frame. He has noticed the following, subsequent to the accident: Physical Examination
Results of physical examination of the external genitalia, anterior abdominal wall, and anal region:
Laboratory Tests Clinical Problems to Consider
Contusions to the scrotum
Subcutaneous fluid infiltration of the scrotum and shaft of the penis
Subcutaneous fluid infiltration of the inferior anterior abdominal wall
Normal anal canal and peri-anal region
Describe the fascial layers of the anterior abdominal wall and male urogenital (UG) region.
Describe the subdivisions of the male urethra.
Explain the contents of the superficial pouch of the male UG region.
Explain the anatomical basis for the signs and symptoms associated with this case.
The male perineum is divided into two regions (Fig. 5.1.1):
Anal triangle (posterior)
Urogenital (UG) triangle (anterior)
Inferior view of the male perineum showing the urogenital and anal triangles. The superficial pouch is opened to reveal its contents.
The plane separating these regions passes through the perineal body at the midline and the anterior aspects of the ischial tuberosities laterally. The anus is the prominent feature for the anal triangle, while the external genitalia dominate the UG triangle. The body (shaft) of the penis and the scrotum are considered part of the UG triangle.
Fascia of the Male Urogenital Triangle
Two distinct layers of the superficial (subcutaneous) fascia can be distinguished on the anterior abdominal wall, and are continuous into the UG triangle (Table 5.1.1). The terminology for these layers is different in each region.
Table 5.1.1Layers of superficial fascia. |Favorite Table|Download (.pdf) Table 5.1.1 Layers of superficial fascia.
|Layer ||Anterior abdominal wall ||Male UG triangle |
|Superficial ||Fatty layer (Camper) ||Muscular layer (dartos) |
|Deep ||Membranous layer (Scarpa) ||Membranous layer (Colles) |
There is a noteworthy difference between superficial layers on the anterior abdominal wall and the UG triangle:
On the anterior abdominal wall, the superficial layer (Camper) is composed primarily of fat.
On the scrotum, the superficial layer (dartos) contains numerous smooth muscle fascicles that insert on the dermis.