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Author9 Posts
  #1

what happens when you massage the neck and carotid sinus is stretched ?




  #2

brady + Hypo?


  #3

I am asking just for carotid body ..


  #4

let me put in a Q form...

Which one of the following will increase if massaging the neck stretches the carotid sinus baroreceptor?

A.Total peripheral resistance
B. Right atrial pressure
C. Venous tone
D. Ventricular contractility
E. Vagal nerve activity


  #5

R Atrial pressure then


  #6

answer given is vagal nerve activity


  #7

hm...may be thats the BEST choice... but the pressure in r atrium will deff go upi guess they are hinting at carotid sheath and it contents when neck is stretched the sheath is under tension, so vagus gets stimulated.


  #8

Yes, its E, increase in vagal nerve activity.

Stretching the carotid baroreceptor simulates increased BP at the carotid baroreceptor, initiating vagal negative feedback.


  #9

Stretching of baroreceptor leads to increased firing and impulse carried from carotid sheath to vasomotor center located in medulla via the glossopharrngeal N(Hering's Nerve)...vasomotor center then causes increased parasympathetic...vagus(and decreased sympathetic) outflow leading to decreased rate and contrctility of the heart muscles and so a drop in the BP.The decreased sympathetic outflow on the other hand decreases the peripheral resistance by slight relaxatiopn of vascular smooth mucles via the alpha 1 receptors.And so there is decreased vasoconstriction of veins so decreased venous return to the heart(because the blood is all pooled into the veins)and so the Rt. Atrial pressure will drop.The decrease inb venous return via the Frank starling law also leads to decrease stroke volume and fall in BP.





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