Chapter 1: Neural Control Of Eye Movements Flashcards
What is the primary action of the medial rectus?
Moves eyes inward.
What are the 6 extraocular muscles?
Medial rectus Lateral rectus Superior rectus Inferior rectus Superior oblique Inferior oblique
What is the primary action of the lateral rectus?
Moves eyes outward.
What is the primary action of the superior rectus?
Moves eyes upward.
Secondary: rotates top of eye toward nose.
What is the primary action of the inferior rectus?
Moves eye downward.
Secondary: rotates top of eye away from nose.
What is the primary action of the superior oblique?
Rotates top of eye toward nose.
Secondary: moves eye downward.
What is the primary action of the inferior oblique?
Rotates top of the eye away from nose.
Secondary: moves eye upward.
What is the cranial nerve innervation of the medial rectus EOM?
Cn III - oculomotor
What is the cranial nerve innervation of the lateral rectus EOM?
CN VI - abducens
What is the cranial nerve innervation of the superior rectus EOM?
CN III - oculomotor
What is the cranial nerve innervation of the inferior rectus EOM?
CN III - oculomotor
What is the cranial nerve innervation of the superior oblique EOM?
CN IV - trochlear
What is the cranial nerve innervation of the inferior oblique EOM?
CN III - oculomotor
What are the primary premotor structures?
Medial longitudinal fasiculus Superior colliculus Superior and lateral vestibular nuclei Lateral vestibular nucleus Pontine excitatory burst neurons Medial vestibular nucleus Repositus hypoglossal (PPH)
What is the function of the medial longitudinal fasiculus?
Central conduit to the motor nuclei for coordinated and synchronized eye movements
What is the function of the superior colliculus?
Generates quick eye movements for orienting to visual or auditory stimuli
What is the function of the superior and lateral vestibular nuclei?
Plays a major role in the generation of the VOR and optokinetic nystagmus.
What is the function of the lateral vestibular nucleus?
Fixes images with head stable and environment moving
What is the function of the pontine excitatory burst neurons?
Generates s ballistic eye movements for acquisition of visual target
What is the function of the medial vestibular nucleus
Stabilizes images during head movement and stabilizes environment
What is the function of the repositus hypoglossal (PPH)
Holds a forever on the fovea
What eye movements are associated with the medial longitudinal fasiculus?
Involved in all classes of eye movements
What eye movements are associated with the superior colliculus?
Saccades
What eye movements are associated with the superior and lateral vestibular nuclei?
VOR and optokinetic
What eye movements are associated with the lateral vestibular nucleus
Optokinetic
What eye movements are associated with the pontine excitatory burst neurons
Saccade
What eye movements are associated with the medial vestibular nucleus?
VOR
What eye movements are associated with the repositus hypoglossal (PPH)?
Together with the MVN (medial vestibular nuclei) it participates in horizontal gaze-holding.
What three factors affect our ability to see in detail?
- Where the target is located
- Whether the target is moving or stationary
- Whether the observer is moving or stationary
What two types of receptor cells are found in retina?
Rods
Cones
Where are cones located?
In and around the fovea, making it the part of the eye with highest spatial sensitivity and the part responsible for visual acuity
What three components can the OMS be organized into?
Motor system
Premotor system
Type of eye movement system
