Professional and Linguistic Assessments Board (PLAB) Practice Exam

What hernia occurs through the rectus abdominis muscle medially and the semilunar line laterally?

1. Femoral hernia

2. Spigelian hernia

3. Hiatal hernia

4. Inguinal hernia

The correct answer is: Spigelian hernia

A Spigelian hernia occurs through the rectus abdominis muscle medially and the semilunar line laterally. This type of hernia is found at the level of the Spigelian fascia, which is the aponeurotic layer between the rectus abdominis muscle and the lateral abdominal muscles. The unique anatomy of the area allows for a potential weakness in the abdominal wall, particularly at points where the muscle transitions to the tendinous insertion. This is why Spigelian hernias are specifically located in that region, distinguishing them from other types of hernias. Femoral, hiatal, and inguinal hernias have distinct anatomical locations and mechanisms. A femoral hernia occurs below the inguinal ligament, a hiatal hernia involves the protrusion of stomach tissue through the diaphragm, and an inguinal hernia typically pushes through the inguinal canal. Thus, Spigelian hernias are characterized by their specific relationship to the rectus abdominis and semilunar line, making this answer the most accurate in this case.