Midsagittal or median plane.
Horizontal or transverse plane.
It is correct to say that a is lateral to b and c, b is medial to a and lateral to c, and c
is medial to a and b. We speak of d as the lateral border. We speak of e as the
The portion marked a is the distal third. The portion marked c is the proximal third.
The end marked d is the distal end. The end marked e is the proximal end.
A cell is the microscopic unit of body organization. (para 1-12)
End of Lesson 1