Final answer:
The lumbar region is the abdominal region that lies immediately to the right and left of the umbilical region.
Step-by-step explanation:
The abdominal region that lies immediately to the right and left of the umbilical region is called the lumbar region.
In the abdomen, there are nine regions that healthcare providers use for reference, and the lumbar region is one of them. The lumbar region is located on either side of the umbilical region, making it the region that lies to the right and left of the umbilical region.
Other examples of abdominal regions include the hypochondriac region, which lies immediately superior to the umbilical region, and the hypogastric region, which lies inferior to the umbilical region.