- Human nervous system | 0, 0, 1
- Human body system | 0, 0, 2
- Human body | 9, 13, 6
- Human | 14, 164, 15
- Mammal | 0, 164, 16
- Chordate | 0, 164, 17
- Animal | 31, 266, 23
- Eukarya | 9, 739, 29
- Species | 0, 4k, 106
- Taxonomy | 12, 5k, 119
- Biology | 0, 10k, 468
- Natural science | 0, 61k, 2k
- Science | 0, 66k, 2k
- Ciro Santilli's Homepage | 262, 218k, 4k