REFLEXES OF THE EYE - MODULE Flashcards Preview

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Flashcards in REFLEXES OF THE EYE - MODULE Deck (30)
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1
Q

What reflex allows for the adjustment of changing light conditions

A

the pupillary light reflex

2
Q

What muscle is responsible for constriction of the pupil?

A

constrictor pupillae

3
Q

what nervous system leads to pupil constriction

A

parasympathetic

4
Q

in the pupillary light reflex, light reaches the retina and informations travels via the optic nerve to the …

A

pretectal nuclei in the midbrain

5
Q

in the pupillary light reflex, fibres from each pretectal nucleus sends bilateral projections to the

A

edinger-westphal nuclei

6
Q

in the pupillary light reflex, preganglionic parasympathetic fibers from the edinger-westphal nuclei travel with the oculomotor nerve to the…

A

ciliary ganglia

7
Q

what is the final step to the pupillary light reflex

A

postganglionic parasympathetic fibres travels as the short ciliary nerves and innervate the contrictor pupillae muscles

8
Q

if the right CN III is damaged, shining light in the right eye will result in

A

no constriction of right pupil but constriction of left pupil

9
Q

The pupillodilator reflex relies on what nervous system

A

the sympathetic

10
Q

When is the pupillodilator reflex activated

A

in response to strong emotional state

11
Q

what muscle is responsible for he pupillodilator relfex

A

the dilator pupillae muscle

12
Q

What initiates the pupillodilator reflex

A

sympathetic neurons in the lateral horn of spinal segment T1 are stimulated by higher brain systems in response to emotional stimulus

13
Q

in the pupillodilator reflex, sympathetic fibres leave the spinal cord and travel up the sympathetic trunk to the…

A

superior cervical ganglion

14
Q

in the pupillodilator reflex, postganglionic fibres travel along the _____ into the cranium

A

carotid artery

15
Q

in the in the pupillodilator reflex, once in the cranium the postganglionic fibres travel to the orbit along the…

A

ophthalmic division of the trigeminal nerve

16
Q

in the pupillodilator reflex, the fibres branch off V1 as the ___ and innervate the dilator pupillae muscles of the iris

A

long cilary nerves

17
Q

What is the pathway called that causes blinking of the eye when the eye senses touch or pain

A

corneal bink relfex

18
Q

in the corneal blink reflex, following sensory stimuli to the cornea, sensory afferent travel via the _______ to the _____

A

ophthalmic division of the trigeminal nerve to the trigeminal sensory nucleus

19
Q

in the corneal blink reflex, sensory afferents synapse with spinal trigeminal interneurons, which project to the

A

facial motor nucleus

20
Q

in the corneal blink reflex, fibres from the facial motor nucleis innervate the

A

circular orbicularis oculi muscles

21
Q

Convergence and divergence of the eyes is caused by signal from the

A

vergence centers

22
Q

where are the vergence centers located

A

in the rostral midbrain

23
Q

the vergence centres signal the ____ causing convergence

A

oculomotor nuclei

24
Q

the vergence centres signal the ____ causing divergence

A

abducens nuclei

25
Q

In order to focus on a near object what 3 things must occur

A
  1. convergence of the eyes
  2. thickening of the lens
  3. constriction of the pupil
26
Q

What area of the brain coordinates the 3 things that must occur in order to focus on something near

A

the supraoculomotor area in the rostral midbrain

27
Q

In the accommodation reflex, the supraoculomotor area sends bilateral projections to the _____ and the _____

A

oculomotor nucleus and the edinger-Westphal nuclei

28
Q

in the accommodation relfex, innervation of the oculomotor nuclei results in ____

A

convergence of the eyes via the activation of the medial rectus muscle

29
Q

in the accommodation relfex, innervation of the edinger-Westphal nuclei results in ____

A

parasympathetic innervation of the constricor pupillae muscles resulting in constriction of the eyes

30
Q

Int he accommodation reflex, what causes the lens to change shape and increase curvature

A

parasympathetic stimulation of the ciliary muscles