One important factor in acountryâs population density is its area. SouthAmerican countries, with their relatively largeland areas, tend to have low population densities.In Ecuador, the most densely populated country inSouth America, an average of only 118 peopleshare a square mile (46 people per sq. km).
Trochlear nerve: The nerve that controls the superior oblique muscle of the eye, one of the muscles that move the eye (extraocular muscles). Paralysis of the trochlear nerve results in rotation of the eyeball upward and outward (and, therefore, in double vision).The trochlear nerve is the fourth cranial nerve, and it is the only cranial nerve that arises from the back of the brain stem.aralysis of the trochlear nerve results in rotation of the eyeball upward and outward (and, therefore, in double vision). The trochlear nerve is the fourth cranial nerve, and it is the only cranial nerve that arises from the back of the brain stem.
When the trochlear nerve (cranial nerve IV) is damaged, a palsy of the superior oblique muscle may occur. Typically, this will resut in an excyclotorsion (outward rotation), along with a lesser hypertropia and esotropia (upward and inward movement) of the affected eye.hen the abducens nerve (cranial nerve VI) is damaged, a palsy of the lateral rectus (LR) muscle may occur, resulting in an esotropia of the affected eye. That eye generally will not be able to look outward past the midline, and it will be somewhat turned inward when the other eye is fixating straight ahead.