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    (Original post by mrs_bellamy)
    Ah I'm so jealous! We never get study leave. They tell us its not possible to revise for our exams (it definitely is).
    They actually tell you that? I wish there was a way to avoid revision here. I detest it.
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    The progress test does have it's up sides
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    Got up at 7 to see my girlfriend off and had to go back to sleep as I was far too tired - not looking good for next week's lectures!
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    (Original post by Woody.)
    Got up at 7 to see my girlfriend off and had to go back to sleep as I was far too tired - not looking good for next week's lectures!
    There is absolutely no chance that i'll be able to stay awake for all of those 9am starts; my body clock is a mess. :colonhash:
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    (Original post by Onychophagia)
    There is absolutely no chance that i'll be able to stay awake for all of those 9am starts; my body clock is a mess. :colonhash:
    Same... I've been up since 8:30am... definitely time for a nap
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    (Original post by Onychophagia)
    There is absolutely no chance that i'll be able to stay awake for all of those 9am starts; my body clock is a mess. :colonhash:
    Next week does not look overly pleasant at all, and I'm struggling to believe that our 'mocks' for our end of year exams are in the next month, I feel that I've picked up absolutely nothing. I'm also surprised that we haven't met yet!
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    (Original post by Onychophagia)
    There is absolutely no chance that i'll be able to stay awake for all of those 9am starts; my body clock is a mess. :colonhash:
    Tell me about it. I'm blaming the Ashes and the silly Australian position on the globe.
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    I'm just trying to revise some (very basic) respiratory stuff, and my book's saying that after a quiet expiration, intrathoracic pressure is about -0.5 kPa. I don't quite understand why, if it is negative relative to atmospheric pressure, air does not continue to enter the lungs, as gasses go from a region of high to low pressure, right? Is it due to some elastic tension in the lungs, or perhaps the intercostal muscles? But further, if it does reach 0 (or +ve as in forced expiration) what prevents the lungs collapsing? The book also says that the terms 'intrapleural pressure' and 'intrathoracic pressure' are interchangeable, does that mean that the pressure inside the thorax is always the same as the pressure inside the pleural membranes? Thanks!
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    Exam 1 out of 2 done today.

    They asked a few riducolous questions (as expected), but otherwise the questions were a bit boring tbh.
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    (Original post by Woody.)
    I'm just trying to revise some (very basic) respiratory stuff, and my book's saying that after a quiet expiration, intrathoracic pressure is about -0.5 kPa. I don't quite understand why, if it is negative relative to atmospheric pressure, air does not continue to enter the lungs, as gasses go from a region of high to low pressure, right? Is it due to some elastic tension in the lungs, or perhaps the intercostal muscles? But further, if it does reach 0 (or +ve as in forced expiration) what prevents the lungs collapsing? The book also says that the terms 'intrapleural pressure' and 'intrathoracic pressure' are interchangeable, does that mean that the pressure inside the thorax is always the same as the pressure inside the pleural membranes? Thanks!
    One of the slides in that lecture confused me; the one that said that intrapleural pressure becomes positive during forced expiration. All other sources i've come across say that intrapleural pressure is always negative. This makes more sense, as the lungs would collapse under a positive intrapleural pressure. The negative pressure is down to the lymphatic system draining pleural fluid and the elasticity of the lungs (inward force) opposing the elasticity of the chest (outward force) giving a greater intraplueral volume and therefore a lower pressure.
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    (Original post by Onychophagia)
    One of the slides in that lecture confused me; the one that said that intrapleural pressure becomes positive during forced expiration. All other sources i've come across say that intrapleural pressure is always negative. This makes more sense, as the lungs would collapse under a positive intrapleural pressure. The negative pressure is down to the lymphatic system draining pleural fluid and the elasticity of the lungs (inward force) opposing the elasticity of the chest (outward force) giving a greater intraplueral volume and therefore a lower pressure.
    Hmm, that would make more sense, however, even Pocock & Richards says that intrapleural pressure becomes positive during forced expiration, up to 10 kPa. So I don't really know what to think!
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    (Original post by Woody.)
    Hmm, that would make more sense, however, even Pocock & Richards says that intrapleural pressure becomes positive during forced expiration, up to 10 kPa. So I don't really know what to think!
    Yeah, i've just seen that. We can be clueless together now! :yy:
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    (Original post by Onychophagia)
    Yeah, i've just seen that. We can be clueless together now! :yy:
    It might make sense if alveolar pressure always remains negative, whilst intrepleural did not. However going by the diagram of pressure against time alveolar pressure (page 320) does become positive and negative throughout a normal breathing cycle. I'm confused.
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    (Original post by Woody.)
    x
    Right, apparently during forced expiration there is local airway collapse (or narrowing) at the equal pressure point (where Intrapleural pressure and Alveolar pressure are equal). The pressure then builds distal to this point which helps to open the airways again.This is not a problem in healthy individuals but is for sufferers of COPD or emphysema.
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    (Original post by Onychophagia)
    One of the slides in that lecture confused me; the one that said that intrapleural pressure becomes positive during forced expiration. All other sources i've come across say that intrapleural pressure is always negative. This makes more sense, as the lungs would collapse under a positive intrapleural pressure. The negative pressure is down to the lymphatic system draining pleural fluid and the elasticity of the lungs (inward force) opposing the elasticity of the chest (outward force) giving a greater intraplueral volume and therefore a lower pressure.

    (Original post by Woody.)
    Hmm, that would make more sense, however, even Pocock & Richards says that intrapleural pressure becomes positive during forced expiration, up to 10 kPa. So I don't really know what to think!
    Guys, I would suggest looking up CPAP and BiPAP - bit of interesting clinical stuff - and it makes sense to do it now...
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    Yay, first day back with a 3 hour symposium on access to healthcare, and 2 hours of neuro introduction, finishing at 4 on a Wednesday. Nice.

    Still, I think I may enjoy neuro, atleast I certainly hope so as it will almost take us up to April.
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    The auditory system truly is horrific.
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    (Original post by i'm no superman)
    The auditory system truly is horrific.
    You mean wonderful right? Along with eyes and vestibular system only bits of (sort of) neuro I like.
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    (Original post by crazylemon)
    You mean wonderful right? Along with eyes and vestibular system only bits of (sort of) neuro I like.
    No way, it's tedious. I prefer looking at the somatosensory-motor complexes that span cortical, subcortical and spinal levels. That's real neuro. It's far more interesting. Who cares about perilymph, endolymph and any other whatever-lymph? :p:
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    (Original post by i'm no superman)
    No way, it's tedious. I prefer looking at the somatosensory-motor complexes that span cortical, subcortical and spinal levels. That's real neuro. It's far more interesting. Who cares about perilymph, endolymph and any other whatever-lymph? :p:
    I loathe that stuff. I know only half the names and then I don't know what I do know does. Other than the substantia nigra, I can do that. But basal ganglia? No thanks. Half the nuclei in the thalamus and all of them in the hypothalmus can **** off :p:
 
 
 
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