Caption

Pelvic anatomy. Artwork of some of the major organs and blood vessels of the pelvic region, including the rectum and anus (lower centre) and sigmoid colon, the final parts of the digestive system. Behind these are the common iliac arteries (red) and common iliac veins (blue) which join to form the inferior vena cava and the abdominal aorta respectively. For each leg, the common iliac blood vessels branch into external and internal blood vessels. This is visible at centre left. Behind the blood vessels are the lower vertebrae of the spine, ending in the fused bones of the sacrum. At left and right are the bones and muscles of the pelvis.