this image shows what is called"sensory dermatomes" every dermatome is the area supplied by single segment of the spinal cord
our body is segmented to several dermatomes accourding to its nerve supply
1. trigeminal nerve "for the face"
2. C2-C5 neck and upper thorax area
3. T1-T12 rest of the thorax and upper abdominal area
4. L1-L5 rest of the abdomen and the pelvic area and the upper leg area
5. S1 the rest of the leg area
6. S2-S4 genital area