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Why does heart rate increase in inspiration?

  1. Jan 15, 2010 #1
    Hello everyone,

    Can anyone explain simply why heart rate increases in inspiration. Also why does the aortic valve close before pulmonary valve in inspiration? In inspiration does superior vena cavae get more blood? From what I read there was something to do with blood pooling inside the lungs during inspiration? Why does blood pool I don't understand?

    Thanks :smile:
     
    Last edited: Jan 15, 2010
  2. jcsd
  3. Jan 18, 2010 #2

    somasimple

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    Lungs are described as an accessory cardiac pump.
    In inspiration, there is a depression (diaphragm) and blood goes more easily in lungs.
     
  4. Jan 19, 2010 #3
    Hey somasimple did you mean blood goes less easily in lungs in inspiration. We learned this in class today!!
     
  5. Jan 20, 2010 #4

    somasimple

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    I said the contrary:
    http://www.nda.ox.ac.uk/wfsa/html/u12/u1211_01.htm [Broken]
     
    Last edited by a moderator: May 4, 2017
  6. Jan 20, 2010 #5
    In my case there seems to be a rather big difference. My heart rate is now about 45 bpm, but I notice that when I'm breathing in, it is above 50 bpm (the beats come almost every second). When I'm exhaling, my heart rate becomes very slow, below 40 bpm.
     
  7. Jan 21, 2010 #6

    somasimple

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    Heart rate and blood pressure are different things. :wink:
     
  8. Jan 25, 2010 #7
    Heart rate increases whereas primarily, it is the blood pressure that decreases. During inspiration, negative intrathoracic pressure fills the pulmonary vasculature temporarily reducing the left atrial input and therefore the stroke volume. An increase in heart rate is a consequence of this.

    In the clinical condition known as pulsus paradoxus, there is exaggeration of these events.
     
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