The upper surface of the tongue is in the anterior zones.
The teeth are in the respective zones as indicated by passing a line antero-posteriorly thru the respective zones.
The viscera are in the zones as represented by a line passed antero-posteriorly thru the respective zones.
Fig. 1.
Diagram of Posterior Zones on one side of the body.
Both right and left sides of the body are the same.
Each numbered line represents the center of its respective zone on the posterior part of the body.