Point 17
Motor V
Sensory
V
Mes
V
Corn. Refl.
Summary
Overview
Problems
Contents
Anatomy
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Damage to the C.N. V results in problems
with the CORNEAL REFLEX. This reflex involves
C.N. V (on the sensory side) and
CN VII (on the motor side). Stimulation of the
cornea of one eye results in the closing of BOTH
eyelids. The pathways involved are (1) touch fibers in the
ophthalmic division of C.N. V (innervate cornea) that pass
into the chief sensory nucleus V, some pain fibers probably
pass into spinal tract V, but lets concentrate on the touch
fibers to the CHIEF. Cells in the CHIEF
project BILATERALLY to motor VII (we can not identify
these axons in our sections). The result is closing of
BOTH eyelids upon stimulation of ONE cornea.
The response on the side that is stimulated is called the
DIRECT corneal reflex while that on the opposite side
is called the CONSENSUAL corneal reflex. Go over the
diagram and think about the results of lesions of the
various components.
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