Two answers required. After meals, a sharp, stabbing pain in the abdomen occurs in underweight patients whose transverse duodenum is being compressed by these two arteries. For 10 points each:
[10h] Identify both of these arteries. In nutcracker syndrome, varicoceles can result from a backed up outflow when the left renal vein is compressed between these two arteries.
ANSWER: abdominal aorta AND superior mesenteric artery [accept SMA in place of “superior mesenteric artery”]
[10m] The obstruction in nutcracker syndrome restricts the flow of blood into this large vessel, which returns blood from the lower body to the right atrium of the heart.
ANSWER: inferior vena cava [or IVC; reject “superior vena cava”]
[10e] Venous return to the heart can also be hindered by the formation of one of these objects in a deep vein, typically in the lower leg or thigh. These objects may then dangerously dislodge and form obstructive emboli in the lungs.
ANSWER: thrombi [or thrombus; accept blood clots or deep vein thrombosis]
<Itamar Naveh-Benjamin, Biology>