1. Classification Symmetry Body Direction

2. Classification of Humans
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Primates
Family Hominidae
Genus Homo
Species sapiens

3. Classification of Dogs
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Canidae
Genus Canis
Species familiaris

4. Animal Symmetry
Asymmetry—no central axis or point
Example: sponge

5. Animal Symmetry
Bilateral symmetry—animal has identical right and left images
Example: crayfish

6. Animal Symmetry
Radial symmetry—any plane passing through the center of animal produces identical mirror images
Example: sea star

7. Terms of Direction in the Body
Aboral—end opposite the mouth
Oral—end containing the mouth

8. Body Direction
Anterior—head end
Posterior—tail end

9. Body Direction
Caudal—toward the tail
Cephalic—toward the head

10. Body Direction
Distal—away from the point of attachment of a structure on the body (toes are distal to the knee)

11. Body Direction
Proximal—toward the point of attachment of a structure on the body (hip is proximal to the knee)

12. Body Direction
Dorsal—back of an animal

13. Body Direction
Ventral—belly of an animal

14. Body Direction
Inferior—below a point of reference (mouth is inferior to the nose)

15. Body Direction
Superior—above a point of reference (the neck is superior to the chest)

16. Body Direction
Lateral—away from the plane that divides a bilateral animal into mirror images

17. Body Direction
Medial (median)—on or near the plane that divides a bilateral animal into mirror images