Visual from book

Question 1

horizontal eye movements

Answer 1

medial rectus towards nose (adduction), and lateral rectus towards temple (abduction)

Question 2

vertical eye movements

Answer 2

superior rectus (upward elevation) and inferior rectus (depression or look downward)

Question 3

superior oblique

Answer 3

intorsion (also because of trochlear connective tissue), depression, and abduction

Question 4

inferior oblique

Answer 4

extorsion and elevation abduction

Question 5

innervation of ocular muscles

Answer 5

superior oblique 4, lateral rectus 6 and all others 3

Question 6

ciliary muscles and ciliary body

Answer 6

connected to lens by suspensory ligament, change curvature of the lens to bring things into focus (lens accommodation)

Question 7

sphincter and dilator muscles

Answer 7

control size of pupil

Question 8

sphincter is controlled by

Answer 8

parasympathetic-> constriction

Question 9

dilator is controlled by

Answer 9

sympathetic-> dilates

Question 10

eyelid muscle

Answer 10

levator palpebrae superioris and orbicularis oculi

Question 11

ocular motor nucleus

Answer 11

mid-line in inferior part of PAG of rostral midbrain. Lying beneath is MLF, which does synapse in ocular motor nucleus

Question 12

supply to CN III motor nucleus

Answer 12

paramedian branches of basilar artery and PCA segments

Question 13

edinger-Westphal complex

Answer 13

Edinger-Westphal centrally projecting nucleus and Edinger-Westphal pre-ganglionic nucleus.

Question 14

EW complex

Answer 14

peptidergic, neurons project to ciliary ganglion to control lens and pupil.
Travel with ipsilateral CN III-> ciliary ganglion (synapse)-> short ciliary nerves->

Question 15

trochlear nucleus

Answer 15

axons cross midline at anterior medullary velum-> exit dorsal surface of brainstem at base of inferior colliculus-> cavernous sinus-> superior orbital fissure

Question 16

abducens nucleus

Answer 16

located in facial colliculi in caudal pons->exits near pontomedullary junction->pass adjacent to medial lemniscus and corticospinal tract

Question 17

abducens internuclear nucleus

Answer 17

transmits signals to medial rectus in contralateral eye via medial longitudinal fasciculus. Lateral rectus of one eye works in tandem with medial rectus of other eye

Question 18

superior cervical ganglion

Answer 18

sympathetic innervation to orbit. Travel with CN III and V.
traveling with CN III-> supply superior tarsal muscle
traveling with CN V-> long ciliary nerves, dilator pupillae muscle

Question 19

cholinergic preganglionic motor neurons

Answer 19

supply superior cervical ganglion located at T1-T3

Question 20

saccades

Answer 20

rapid movements from one point to another, function to bring targets into eye fields, visual input supressed during movements, voluntary and reflexive

Question 21

fixation points

Answer 21

places where detailed visual inspection occurs

Question 22

burstonic firing pattern

Answer 22

“pulse and step” pattern

Question 23

Pulse part of burstonic

Answer 23

initial burst of motor neuron activity that directs the phasic portion of movement producing muscle contraction necessary for to overcome viscosity of orbit and send globe towards target

Question 24

Step part of burstonic

Answer 24

supports tonic action of muscles which maintains eye in new position

Question 25

PPRF

Answer 25

paramedian pontine recticular formation (horizontal gaze center)-> projects to extra-ocular motor nuclei

Question 26

PPRF location

Answer 26

oral and caudal pontine reticular nuclei

Question 27

PPRF cells

Answer 27

extra-ocular motor neurons: excitatory burst neurons->rostral to 6th nucleus inhibitory burst neurons-> caudal to 6th nucleus

Question 28

supra-nuclear structures for PPRF

Answer 28

superior colliculus, frontal eye field, and EBN and IBN gated by inhibition from pontine tegmentum (omnipause cells)

Question 29

omnipause cells fire during

Answer 29

fixation (silent during saccade)

Question 30

vertical gaze

Answer 30

located in rostral interstitial nucleus of MLF, Sam supra-nuclear input as horizontal gaze

Question 31

tonic signaling for horizontal and vertical

Answer 31

horizontal: nucleus prepositus hypoglossi vertical: interstitial nucleus of Cajal

Question 32

where do connections between two interstitial nuclei of Cajal cross?

Answer 32

posterior commissure

Question 33

PPRF, riMLF, and intersitial nucleus of Cajal recieve input from?

Answer 33

cortical and collicular projections

Question 34

PPRF, riMLF, and intersitial nucleus of Cajal recieve projections are called?

Answer 34

reticulospinal and intersitiospinal fibers (and a small contribution from tectospinal portion of tectoritculospinal)

Question 35

area of brain that directs saccade movement?

Answer 35

cortical eye field and superior colliculus

Question 36

frontal eye field

Answer 36

rostral to motor cortex, middle frontal gyrus in BA 6 | gets input from visual association cortex and thalamic relays (paralamellar dorsomedial nucleus)

Question 37

frontal eye field influences?

Answer 37

eye movements through projections to vertical and horizontal gaze centers and to superior colliculus

Question 38

superior colliculus

Answer 38

roof of midbrain. Blood supply from quadrigeminal artery (PCA).

Question 39

superficial layer of superior colliculus

Answer 39

visual sensory-> target of retinal axons with M and K type, projections to dorsal lateral geniculate and pulvinar nuclei

Question 40

intermediate layer of SC

Answer 40

visual motor->source of crossed tectoreticulospinal system and runs verticall to MLF-> terminates in vertical and horizontal gaze centers

Question 41

inputs to intermediate layer of SC

Answer 41

cortical eye fields and substantia nigra

Question 42

types of saccades for frontal eye field and SC

Answer 42

SC: reflexive orienting movement | frontal eye field: voluntary and memory guided eye movements

Question 43

neurons sensitive to speed and direction of target moving across the retina?

Answer 43

lateral parietal and mid-temporal cortices

Question 44

neurons that display pursuit-related motor activity?

Answer 44

frontal eye field

Question 45

frontal eye field, lateral parietal and mid-temporal project to?

Answer 45

flocculus and paraflocculus of cerebellum by way of posterolateral pons (also provides input to vestibular nuclei)

Question 46

smooth pursuit premotor neurons are associated with which neurons?

Answer 46

3,4,6

Question 47

what is the near triad or near response?

Answer 47

looking from a distant target to a closer one. 3 changes are made 1. ) eyes converge by action of both medial rectus muscles to point fovea at closest target 2. ) curvature of lens is increased-> increasing refractive power 3. ) pupil constricts

Question 48

what happens when a gaze is shifted from a closer to farther away object?

Answer 48

divergence, flattening of lens, and pupillary dilation

Question 49

premotor neurons that correlate with near response activity are found

Answer 49

in supra-oculomotor area (SOA)

Question 50

which reflex compensates for continuous-velocity movements?

Answer 50

opto-kinetic system

Question 51

retinal slip

Answer 51

whole field movement of visual scene

Question 52

what controls vergence?

Answer 52

retinal disparity, cells in visual cortex with binocular visual fields are activated when retinal images have disparity.

Question 53

vergence?

Answer 53

slower than saccade, they usually occur in combination with saccades

Question 54

accessory optic tract

Answer 54

axons of retinal ganglion cells that terminate in a series of small nuclei along incoming optic tract

Question 55

nuclear and infranuclear pathway

Answer 55

brainstem nuclei, CN III, IV, VI, extra and intra ocular muscles

Question 56

supranuclear pathway

Answer 56

brainstem, forebrain circuits that control eye movements via CN III, IV, VI