Busy. Please wait.
Log in with Clever

show password
Forgot Password?

Don't have an account?  Sign up 
Sign up using Clever

Username is available taken
show password

Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Vis Reflexes

Visual Reflexes & Eye Movements

Direct Light Reflex Afferents Retina, CN 2, optic tract > Superior Colliculus > Interneurons > E-W nucleus
Direct Light Reflex Efferents E-W nucleus via CN 3 > ciliary ganglion & sphincter mm of eye
Problems with Light Reflex Damaged retina/CN 2- if complete blindness, loss of both direct & consensual reflex when light shown in damaged eye; No problems w/ reflex w/ damaged LGN, optic radiations, visual cortex of 1 side or cortical blindness
When object close to face Convergence Pupillary constriction Near rxn Accomodation
Accommodation Afferent Limb Optic n, chiasm, & tract; LGN & optic radiation to visual cortex; Visual cortex connected to frontal EF; From EF, fibers descend through IC to CN 3; From EF, other cortical fibers synapse w/ PNS fibers (E-W nuc) Causes pupil constriction
Adie's Tonic Pupil Lesion of PNS ciliary ganglion/nerves; Benign unilateral dilated pupil; Decreased/no light reflex; slow contraction to near vision; slow dilation in dark
Argyll Robertson Pupil Small, irregular pupil no reaction to light; Does react to accommodation; Interruption of fibers running from pre-tectal nucleus to E-W nucleus
Marcus Gunn Paradoxical dilation both pupils that occurs when light shown in symptomatic eye AFTER shown in normal eye
Saccadeic Sub-system Places fovea on target rapidly & accurately--fixation
Saccadic Sub-systems Volitional; Reflexive; Volitional visually guided: actively look & find object (something particular); Reflexive visually guided: combination w/ pursuit; someone says ball is coming & you look at it
Lesions to Saccadic Pathway Hypometria- saccades too small; Dysmetria- too slow & inaccurate Saccadic palsy- delayed onset/no saccadic activity
How to test saccades Have pt look b/t 2 wide-set objects
Pursuit mvmts Fixation on slowly moving objects; if it fails, saccades must catch up
Lesion of Pursuit Movements Movement of object off fovea > saccade, no pursuit > series of small saccades to follow target
Vestibulo-Ocular Reflex Prevents image from moving off fovea
Vestibulo-Ocular Afferent Hair cells in semi-circular canals to ipsilateral vestibular nuclei
Vestibulo-Ocular Efferent Vestibular nuclei to extraocular mm.
How would you test for vestibulo-ocular reflex? Doll's Eye
Otokinetic Sub-system Eye mvmts in reponse to retinal slip during head mvmt at constant velocity; Direct path: retina, optic tract nuclei- cblm/vestibular nuclei
Created by: 1190550002
More popular Physical Therapy sets




Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
restart all cards