CV Review, Essentials, Develop. Physiol., Dr. D. Penney



Table 1.06. Postural Effects of Orthostasis on Blood Pressure

  • Head
  • arterial pressure = (100 -5*) - 44 = 51
    venous pressure = 5 - 44 = - 39

    perfusion pressure = 51 - (- 39) =90

  • Feet
  • arterial pressure = (100 - 5*) + 88 = 183
    venous pressure = 5 + 88 = 93

    perfusion pressure = 183 - 93 = 90

    Note: Assumes that resistance has not changed in going from the supine to orthostatic position, which in reality, is not true.
    * The 5 mmHg subtracted from both arteries and veins is due to the vascular resistance between the heart and the head and between the heart and the feet.


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