Answer to Worm Man
Correct answer is C. The rationale for this is that the left gonadal vein drains to the left renal vein. The flow in the latter can be compromised because it is sandwiched by the superior mesenteric artery and the aorta. In contrast, the right gonadal vein drains directly into the IVC and its flow is much less likely to be compromised. Hence, varicoceles are more common on the left side of the scrotum than the right. The Valsalva procedure is performed by forceful attempt at exhalation against a closed airway, the act which mimics the straining during defecation. During the strain, the venous return to the heart is decreased and peripheral venous pressures become increased. The relative venous diameter changes become more pronounced in varicose veins and the varicoceles are more easily detected. In women, an analogous varicosity of the Salpingo-ovarian complex is rare.
= Formation of IVC
= IVC superior to entry of right gonadal vein
= Left renal vein
= Left gonadal vein
= Posterior abdominal wall covering descending colon
Answer to this question is based on material presented in lectures 7 of the Abdomen Lecture Series.
