Prep for USMLEPrep for USMLE Forum
   Forum    Step 1  Step 2 CK Step 2 CS Step 3  Match  IMGs Resources Search






Previous Topic | Next Topic  Pupillary Light Reflex 




 
Kaplan Qbank USMLE



Author4 Posts
  #1

If you shine light from a pen torch in one eye, you get the direct and consensual pupillary reflexes, and both pupils constrict by equal amounts.

What happens if you shine light using two pen torches, one in each eye, but with different intensities? I think that both eyes will constrict by equal amounts, to the size appropriate to the highest light intensity, but I'm not sure. Or perhaps light input from both eyes summates in the pretectal and Edinger-Westphal nuclei, and both eyes respond appropriately to this?

If anyone has a reference I can look up I'll be very very grateful.

Thanks everyone,

Moc

  #2

Thats more for an opthamology service/Step 1 is basic. Good luck!

___________________
Smell the coffee! "Is That an Osler move??"

  #3

both pupila will be the same size...anisocoria ( dif in size ) is likely due to an EFFERENT defect.....
afferents from the visual pathway cross over and project bilaterally ..so no dif in size between the two pupils in an afferent pathway

___________________
If you yourself are at peace, then there is at least some peace in the world.

  #4

i agree with studying as far as i understand light reflex isnt it all or none?







You don't have permission to post.




Login or Register to post messages in this topic





















Contact | Leaders | Disclaimer | Privacy

Copyright @ Prep for USMLE. All rights reserved.