English: The image depicts the Superior Mesenteric Artery (SMA) Syndrome, a condition where the third part of the duodenum is compressed between the SMA and the abdominal aorta, leading to obstruction. The key elements identified are:

Normal anatomy with adequate space between the SMA and the aorta. Reduced angle between the SMA and the aorta, causing pressure on the duodenum. The duodenum, which is the part of the small intestine affected by the compression.

The aorta, the main artery of the body supplying oxygenated blood to the circulatory system.