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pparalpha
Hyotension will lead to decreased arterial pressure and DECREASED stretch. This leads to decreased afferent barcreceptor firing (carotid sinus and aortic arch). This leads to an increase in efferent sympathetic firing and decreased efferent PNS stimulation. This leads to vasoconstriction, increased HR and increased BP.
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sahusema
The way I remember this, carotid massage slows the heart. So baroreceptor stimulation (more impulses) increases parasympathetic output.
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cienfuegos
FA 2018 pg 291 has helpful image/description
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l0ud_minority
MY thought process even though its wrong. The carotid baroreceptros are responsive to both increased and decreases in BP so it should have increased impulses in both scenarios with regulation of sympathetic or parasympathetic depending on the situation.
Vs the aortic arch baroreceptors only respond to high BP not low BP.
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an_improved_me
I always harken back to "don't overcomplicate these questions", but sometimes, NBME requires making some leaps of logic. The trick is knowing when the question requires such a leap... I haven;t gotten very good at that.
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submitted by haldol(12)
BP is low so obviously the body will want to respond by increasing sympathetics and decreasing parasympathetics. since the BP is low, there is less pressure against the wall of the carotid sinus -- meaning less stimulation and fewer impulses. fewer carotid impulses means fewer parasympathetics