Name_________KEY______________

VS 117: Oculomotor Functions and Neurology

Spring 2000

(4 points) List two ways that motor neurons increase innervation for muscle contraction.

Recruitment

increased firing rate.

(4 points) Define Heringís law.

Yoked movements of the two eyes result from equal innervation to yoked muscle pairs.

(4 points) List the two pre-motor nuclei that control the burst innervation for horizontal and vertical saccades.

a. Horizontal- PPRF

b. Vertical- riMLF

(4 points) What is Parinaudís syndrome and where is the lesion that causes it?

Paralysis of vertical gaze resulting from a lesion near the riMLF

(4 points) List four factors that reduce vision during saccades?

smear

backward masking

suppression

retinal shear

(4 points) Define Donderís law.

The torsion of the eye in any given position is independent of how the eye reached that eye position