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Medical Neuroscience help please

  1. Dec 5, 2006 #1
    I'm absolutely clueless so please help if you can...

    - What is the difference between a motor and sensory aphasia?

    - What happens to the pupil reflex in a patient with contical blindness?

    - If a patient has a meningioma in the dura of the falx cerebri at the level of the precentral gyrus, what part of the body will show motor weakness first?

  2. jcsd
  3. Dec 12, 2006 #2


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    I'm going to assume this is for a class, so am not going to answer outright.

    What part of this do you need assistance with? Do you know what an aphasia is? If so, think about what differences might generally exist between any motor disorder and any sensory disorder, and see if you can apply those to the case of aphasia.

    What is cortical blindness? Where does the impairment occur? Where is the reflex arc located?

    The key here is to think about where the falx cerebri is located relative to the precentral gyrus (i.e., what area of the precentral gyrus is going to be affected?), in other words, half the question is just identifying the anatomical relationship between the falx cerebri and the precentral gyrus. From there, you need to recall what parts of the precentral gyrus affect what parts of the body in order to identify the function.
  4. Dec 17, 2006 #3
    thanks for the (semi i suppose) help...

    I have only learnt one clinical thing about it in 4 weeks... but anyway if damage only one half of the spinal cord... You lose nociception (spinothalamic pathway) from the opposite side of the body and proprioception (dorsal column pathway) from the same side of the body as the damage... This is becase the spinothalamic crosses the midline in the spinal cord but the dorsal column pathway crosses in the brainstem...

    But this is really all I know... and considering we have questions like Mr X has *list of 5 words you've never heard of*... and when you look them up it says that he can't talk, he has problems communication, he can't feel pain in this 3rd toe and he can jump on every day except for sunday... and then you find what does he have... and in the question it turned out to be something really weird - it turned out to be posterior cerebral artery blockage... i mean, how the hell am i supposed to know that?!... i don't even do clinical stuff now... only goes to show why you shouldnt work late... it is v counter productive
  5. Dec 17, 2006 #4


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    This is very much how clinical cases present themselves though. Someone says, "Lately, my left big toe seems to be going numb," and you need to know how to trace back the pathway to figure out where the problem is occurring. Are any other toes numb? Any other body parts affected? Are reflexes intact? Any known injuries to extremities? It's problem solving.

    Most of the terms are just anatomical locations, so you can look them up on a brain atlas. It seems like your instructor is trying to push you to take your lesson a step further, so you understand how the anatomy relates to the function, which is the relevant part of neuroscience.

    A lot of it is tracing nerve pathways from periphery to where they join the CNS. It's somewhat like troubleshooting an electrical problem in your home...tracing circuits. A lightbulb in the basement is out, where is the problem? Is it just a burnt out bulb? Is there a short in the connection? Where? Are other lights on that circuit affected? Which ones? What about the rest of the house wiring? Are there lights controlled by the same switch that work? Where do the affected lights join into the circuit? Is the problem in a junction box, or all the way back at the circuit breaker? Studying functional neuroanatomy is very similar, but there are a LOT more connections (more like troubleshooting a power failure in a large city than a lightbulb out in your house).
  6. Dec 29, 2006 #5

    Math Is Hard

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    That's such a wonderful analogy, Moonbear.

    You do know I plan on stealing it for a future essay exam.:devil: :biggrin:

    Seriously, I thought that was a brilliant explanation.
  7. Dec 30, 2006 #6
  8. Dec 30, 2006 #7
    They were second year uni questions I had to answer...

    Yes, I do know what aphasia is... It is loss of ability to speak or understand language

    Broca's aphasia - patient can't speak but can interpret speech

    Wernicke's aphasia - patient can speak but can't interpret speech

    Cortical blindess is where you have no vision in your eyes... It is caused by complete loss of the primary visual corticies on the occipital lobe... but the responce to light 'pupillary reflex' is still functional... and so you still get pupilary contraction when you shine a light into the eye...

    interestingly - well i thought it was interesting...

    if you shine a light into the left eye on a normal person then both the pupils contract... i am not sure about the reflex arc - i did learn about it but it was a bit beyond me...

    Yes, I understand this now... Connecting neuroanatomy to function is tough though...
  9. Dec 30, 2006 #8
    Ok... I do understand things better now... I was just a bit swamped by info a few weeks ago and it takes a while to digest it... and it takes awhile to learn the lingo...

    I understand the signs of lower motoneurone and upper motoneurone lesions... so that's a lot of conditions covered already... and I know about some visual defects - monooccural blindness, bitemporal hemianopias + homozygous hemianopia... Broca's and Wernicke's Aphasias and Brown-Sequard's syndrome...
  10. Jan 9, 2007 #9


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    Yes, the terminology is half the battle. :biggrin: Welcome to PF (if a bit belated). I've heard of people copying homework answers before, but this is the first I've seen someone copy the questions. I guess they were too curious to wait for the answers received elsewhere. :rofl:
  11. Jan 10, 2007 #10
    Thanks... it did take me a while to realise what PF stood for... lol
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