Sonja is a fictional character from the Underworld series of films. This character is the daughter of the vampire elder Viktor, introduced by flashback, in Underworld. Red Sonja, the She-Devil with a Sword, is a fictional character who first appeared in Conan the Barbarian #23 (Marvel Comics).
tetralogy (plural tetralogies) 1  A set of four works of art that are connected, and that can be seen either as a single work or as four individual works. They are commonly found in literature, film, or video games. ( 2 medicine) A combination of four symptoms.
MedlinePlus Dictionary defines tegmentum as the part of the ventral midbrain above the substantia nigra formed of longitudinal white fibers with arched transverse fibers and gray matter. The term ventral refers to the part of the tegmentum located toward the front of the human body rather than the rear. If you look carefully at the image below, you can see two blackish areas, mirror images of each other, in the area labeled 3. These are the substantia nigrae.